AFO NMR Domain Ontology (WD/2026/06)
type: Ontology
imports: afo
imports: nmr
issued: 2026-07-08T12:00:00Z
license: Creative Commons Attribution 4.0 International Public License
modified: 2026-03-30T12:00:00Z
rights: Derivative works attribution
rights: © 2020 Allotrope Foundation
prior version: nmr
version info: WD/2026/06

multiplicity
type: ObjectProperty
range: multiplicity code
definition: The peak multiplicity observed for a coupled system in a chemical moeity. [Allotrope]

benchtop nuclear magnetic resonance spectrometer
type: Class
subclass of: AFE_0000644
definition: A low frequency nuclear magnetic resonance spectrometer that is significantly more compact and portable than the conventional free standing equivalents. [Allotrope]

nuclear magnetic resonance probe outer RF coil
type: Class
subclass of: nuclear magnetic resonance probe RF coil
definition: One of two small coiled electromagnets that perturbs the bulk magnetisation of a sample from equilibrium through a series of RF pulses and records the minute electrical signals as the bulk perturbed magnetisation relaxes back to its equilibrium state. The outer coil is the second RF coil of two wound on top of each other, the one furtherest away from the sample that is least tightly coupled to the sample under investigation. [Allotrope]

broadband nuclear magnetic resonance probe
type: Class
subclass of: AFE_0000084
alternative label: dual broadband nuclear magnetic resonance probe
change note: 2024-09-11 Changed [Amgen] attribution to [Allotrope] and fixed typo in prefLabel.
definition: Tunable NMR spectrometer probe containing at least one channel with a broad tuning range. One RF channel is generally optimized for 1H observation and decoupling and not broadband, but can sometines be tuned to 19F. The second RF channel is generally used for the observation of nuclei other than 1H (eg. 13C, 15N). [Allotrope]

nuclear magnetic resonance tube
type: Class
subclass of: AFE_0000718
AFX_0002798: true
AFX_0002809: OBI_0000578
alternative label: NMR tube
definition: The sample-tube holds the NMR sample and sits in the NMR probe. It is usually a fused quartz tube of 1.7 to 20 mm diameter. [Allotrope]

nuclear magnetic resonance shigemi tube
type: Class
subclass of: nuclear magnetic resonance tube
AFX_0002798: true
alternative label: NMR shigemi tube
change note: 2024-09-11 Changed [Amgen] attribution to [Allotrope].
definition: A Shigemi tube is a microscale NMR tube that uses susceptibility-matched glass to reduce the sample size within the RF coil region. Shigemi tubes may be appropriate for mass-limited sample. [Allotrope]

nuclear magnetic resonance spectrometer inner dewar
type: Class
subclass of: nuclear magnetic resonance dewar
AFX_0002798: true
alternative label: inner dewar
definition: The inner dewar of the NMR spectrometer containing the liquid helium. [Allotrope]

nuclear magnetic resonance outer dewar
type: Class
subclass of: nuclear magnetic resonance dewar
AFX_0002798: true
alternative label: outer dewar
definition: A dewar in the NMR spectrometer that surrounds the inner dewar and contains liquid nitrogen. [Allotrope]

nuclear magnetic resonance cryoprobe
type: Class
subclass of: AFE_0000084
definition: NMR spectrometer probe where the sample remains at ambient or regulated temperature, and the probe RF coils and preamplifiers are typically cooled to around 10-15 K to aid in signal sensitivity and reducing the signal-to-noise (S/N) ratio. [Allotrope]

nuclear magnetic resonance dewar
type: Class
subclass of: AFE_0000852
subclass of: AFE_0001187
AFX_0002798: true
definition: A tank inside the NMR spectrometer to support the cooling of some of the NMR probe electronics down to superconducting temperatures. [Allotrope]

nuclear magnetic resonance spinner
type: Class
subclass of: AFE_0000354
alternative label: NMR spinner
definition: A device that firmly holds the NMR tube in place to avoid the sample wobble and sample field inhomogeneity in the magnetic field. The spinner is spun by nitrogen or anhydrous aid at about 20Hz inside the NMR spectrometer. The spinner also serves as a loosly fitting piston head so that the sample can be slowly inserted into and slowly retrieved from inside the NMR spectrometer via gas flow/pressure. [Allotrope]

nuclear magnetic resonance probe inner RF coil
type: Class
subclass of: nuclear magnetic resonance probe RF coil
definition: One of two small coiled electromagnets that perturbs the bulk magnetisation of a sample from equilibrium through a series of RF pulses and records the minute electrical signals as the bulk perturbed magnetisation relaxes back to its equilibrium state. The inner coil is the first RF coil of two wound on top of each other, that is closest to the sample, that gives best sensitivity as it is closest to and most tightly coupled to the sample under investigation. [Allotrope]

nuclear magnetic resonance probe RF coil
type: Class
subclass of: AFE_0000354
definition: The small coiled electromagnet that perturbs the bulk magnetisation of a sample from equilibrium through a series of RF pulses and records the minute electrical signals as the bulk perturbed magnetisation relaxes back to its equilibrium state. [Allotrope]

nuclear magnetic resonance tuning rod
type: Class
subclass of: AFE_0000354
definition: A rod exposed on the NMR probe to manually tune a broad band probe to an X nucleus. [Allotrope]

quadruple nuclear magnetic resonance probe
type: Class
subclass of: AFE_0000084
definition: Tunable NMR spectrometer probe that may be tuned to pulse up to four nuclei in a single NMR experiment. [Allotrope]

lock system
type: Class
subclass of: AFE_0000354
definition: The lock system is a device that locks the magnetic field strength of an NMR spectrometer at a desired, constant value. [Allotrope]

solid state nuclear magnetic resonance spectrometer
type: Class
subclass of: AFE_0000644
alternative label: solid state NMR spectrometer
alternative label: ssNMR spectrometer
definition: A solid state NMR spectrometer is a type of nuclear magnetic resonance spectrometer that allows for measurement of solid samples. [Allotrope]

double channel probe
type: Class
subclass of: broadband nuclear magnetic resonance probe
alternative label: HX
alternative label: HX probe
alternative label: HY
alternative label: HY probe
definition: A double channel probe is a type of NMR tube that allows for measurements of two different nuclei at the same time. [Allotrope]

triple channel probe
type: Class
subclass of: broadband nuclear magnetic resonance probe
alternative label: HCN
alternative label: HCN probe
definition: A triple channel probe is a type of NMR tube that allows for measurements of three different nuclei at the same time. [Allotrope]

rotor
type: Class
subclass of: nuclear magnetic resonance tube
AFX_0002798: true
AFX_0002808: OBI_0000523
alternative label: ssNMR tube
definition: A rotor is a type of NMR tube usually made of Zirconia that allows for solid state NMR measurements. It can rotate at high frequencies. [Allotrope]

thin wall rotor
type: Class
subclass of: rotor
AFX_0002798: true
definition: A thin wall rotor is a type of ssNMR tube with a thin wall diameter. [Allotrope]

rotor cap
type: Class
subclass of: AFE_0001648
definition: A rotor cap is a type of cap to seal ssNMR tubes. [Allotrope]
example: Vespel cap, Kel-F cap

thick wall rotor
type: Class
subclass of: rotor
AFX_0002798: true
definition: A thick wall rotor is a type of ssNMR tube with a thick wall diameter. [Allotrope]

pulse generator
type: Class
subclass of: AFE_0000354
alternative label: radiofrequency transmitter
alternative label: transmitter
alternative label: waveform generator
definition: A pulse generator is a device that generates electromagnetic pulses with a certain waveform. [Allotrope]
example: pulse generator of an NMR spectrometer

magic angle spinning controller
type: Class
subclass of: AFE_0000354
definition: The magic angle spinning controller is a device that allows for setting up and controlling the properties of the magic angle spinning. [Allotrope]

ceramic rotor
type: Class
subclass of: rotor
AFX_0002798: true
alternative label: MAS rotor
alternative label: rotor
definition: A ceramic rotor is a type of ssNMR tube that consists of ceramic material. [Allotrope]
note: The size of the rotor is typically given by the outer diameter of the rotor, for example, 4.0 mm, 2.5 mm and 1.3 mm are standard rotor sizes.

shim
type: Class
subclass of: AFE_0000354
alternative label: shim system
definition: A shim is a device that allows for adjustment of the homogeneity of a magnetic field. [Allotrope]

standard bore magnet
type: Class
subclass of: AFE_0000882
AFX_0002798: true
alternative label: SB magnet
definition: A standard bore magnet is a superconducting magnet that has a standard bore. [Allotrope]

wide bore magnet
type: Class
subclass of: AFE_0000882
AFX_0002798: true
alternative label: WB magnet
definition: A wide bore magnet is a superconducting magnet that has a wide bore. [Allotrope]

accordion spectroscopy
type: Class
subclass of: AFP_0000759
definition: A dimensionality reduction technique used in multidimensional NMR experiments. A nD NMR experiment is represented in n-1 dimensions by concerted, simultaneous interrogation of two spectral dimensions. [CHMO]

selective insensitive nuclei enhancement by polarization transfer
type: Class
subclass of: insensitive nuclei enhancement by polarization transfer
alternative label: selective INEPT
definition: A heteronuclear NMR experiment in which magnetization arising from 1H nuclei is transferred to covalently bound heteronuclei, thereby enhancing the NMR signal of the heteronuclei. Selective pulses, that only excite or 'select' some of the signals in the spectrum are used in this experiment. [CHMO]

pulsed electron nuclear double resonance spectroscopy
type: Class
subclass of: electron nuclear double resonance
alternative label: pulse ENDOR
alternative label: pulse ENDOR spectroscopy
alternative label: pulsed ENDOR
alternative label: pulsed ENDOR spectroscopy
definition: A type of spectroscopy where a microwave frequency pulse is used to saturate the electron resonance transitions in a sample, and a radio frequency pulse is used excite a nuclear transition. [CHMO]

correlation spectroscopy-nuclear Overhauser enhancement spectroscopy
type: Class
subclass of: homonuclear three-dimensional nuclear magnetic resonance spectroscopy
alternative label: 3D COSY-NOESY
alternative label: 3D-COSY-NOESY
alternative label: COSY-NOESY
definition: A type of homonuclear three-dimensional NMR experiment in which a second frequency dimension is employed to disperse the signals and reveal correlations between nuclei which are J-coupled (usually <= 3 bonds apart). These signals are then correlated to nuclei that are spatially proximate within the molecule (<= 6 Angstrom apart). [CHMO]

heteronuclear decoupling
type: Class
subclass of: nuclear magnetic resonance decoupling
definition: The nuclei being irradiated with an RF pulse is a different nuclei or the same nuclei and a different isotope that the nuclei being observed to relax back to equilibrium for generation of the NMR spectrum. [Allotrope]

bilinear rotation decoupling pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: BIRD
alternative label: bilinear rotation decoupling
definition: A pulse cluster (a spin echo on 1H with inversion of 13C in the centre) used to achieve selective inversion of 12C-bound protons, thus achieving the removal of signals due to 12C-bound nuclei. For the pulse sequence see Chem. Phys. Lett., (1982), 93, pg 504. [CHMO]

two pulse phase modulation pulse sequence
type: Class
subclass of: magic angle spinning decoupling pulse sequence
alternative label: TPPM
alternative label: TPPM pulse sequence
alternative label: TPPM sequence
alternative label: two pulse phase modulation
alternative label: two-pulse phase modulation
definition: A continuous sequence of pulses used in magic angle spinning NMR to remove the effects of heteronuclear dipolar coupling. For the pulse sequence see J. Chem. Phys., (1996), 103, pg 6951. [CHMO]

pulsed field-gradient spin echo nuclear magnetic resonance spectroscopy
type: Class
subclass of: nuclear magnetic resonance diffusometry
alternative label: PFG-SE NMR
alternative label: PFGSE
alternative label: PFGSE-NMR
alternative label: PGSE
alternative label: pulsed field gradient (PFG) spin echo
alternative label: pulsed field gradient spin-echo
alternative label: pulsed field gradient-spin echo
alternative label: pulsed field-gradient spin echo
alternative label: pulsed-field-gradient spin-echo NMR spectroscopy
definition: An NMR experiment in which pulsed field gradients are applied to a spin echo sequence to cleanly and precisely excite particular resonances. Additionally, attenuation of signals occurs related to molecular diffusion allowing this technique to be used to determine self-diffusion coefficients. [CHMO]

gradient-selected heteronuclear multiple bond coherence
type: Class
subclass of: heteronuclear multiple bond coherence
alternative label: GHMBC
alternative label: gHMBC
alternative label: gradient heteronuclear multiple bond coherence
alternative label: gradient-selected HMBC
definition: A type of heteronuclear NMR spectroscopy where pulsed-field gradients are used and a second frequency dimension is employed to disperse the signals and reveal correlations between protons and nuclei which are 2-3 bonds removed. [CHMO]

95Mo electron nuclear double resonance spectroscopy
type: Class
subclass of: pulsed electron nuclear double resonance spectroscopy
alternative label: 95Mo ENDOR
alternative label: 95Mo ENDOR spectroscopy
alternative label: molybdenum-95 ENDOR
alternative label: molybdenum-95 ENDOR spectroscopy
definition: A type of spectroscopy where a microwave frequency pulse is used to saturate the electron resonance transitions in the 95Mo nuclei of a sample, and a radio frequency pulse is used excite a nuclear transition. [CHMO]

quadrupole Carr-Purcell-Meiboom-Gill using magic-angle spinning
type: Class
subclass of: quadrupole Carr-Purcell-Meiboom-Gill experiment
alternative label: MAS QCPMG
alternative label: MAS-QCPMG
alternative label: QCPMG MAS
alternative label: QCPMG-MAS
definition: An NMR experiment used to enhance the sensitivity of low gyromagnetic ratio nuclei by collapsing the intensity of the 'full' spectrum into discrete 'spikelets'/peaks. The intensities of the peaks vary according to the spin-spin relaxation rate (T2) and the envelope described by these peaks represents the full, static spectrum. The solid sample is spun rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field) to reduce line broadening. [CHMO]

inversion recovery
type: Class
subclass of: AFP_0000759
alternative label: inversion recovery Fourier transform
alternative label: IRFT
alternative label: T1
alternative label: relaxation time measurement
definition: An NMR experiment which measures spin-lattice (T1) relaxation rates by acquiring spectra at different delay times following inversion of the spin-state populations. [CHMO]

chemical shift anisotropy experiment
type: Class
subclass of: AFP_0000759
alternative label: CSA experiment
definition: An NMR experiment in which differences in chemical shift are used to give information about the orientation of those spins with respect to the field and, thus, the orientation of the molecule. [CHMO]

J-spectroscopy
type: Class
subclass of: two-dimensional nuclear magnetic resonance spectroscopy
alternative label: 2D J-resolved spectroscopy
alternative label: 2D J-spectroscopy
alternative label: 2DJ spectroscopy
alternative label: J-RES
alternative label: J-resolved NMR
alternative label: J-resolved NMR spectrometry
alternative label: J-resolved NMR spectroscopy
alternative label: J-resolved spectrometry
alternative label: J-resolved spectroscopy
alternative label: J-resolved spectroscopy NMR spectroscopy
alternative label: J-spectrometry
alternative label: JRES
alternative label: JRES NMR
alternative label: two-dimensional J-spectroscopy
definition: A type of homonuclear proton-proton NMR spectroscopy where chemical shift and J-coupling information are separated onto different frequency axes. [CHMO]

decoupling using mind-boggling optimization pulse sequence
type: Class
subclass of: magic angle spinning decoupling pulse sequence
alternative label: DUMBO
alternative label: DUMBO pulse sequence
alternative label: DUMBO sequence
alternative label: decoupling using mind boggling optimization
alternative label: decoupling using mind-boggling optimization
definition: A sequence of pulses used in magic angle spinning NMR to remove the effect of homonuclear dipolar couplings. For the pulse sequence see Chem. Phys. Lett., (2004), 398, pg 532. [CHMO]

exorcycle
type: Class
subclass of: phase cycle
alternative label: EXORCYCLE
definition: A phase cycle technique used in FT NMR experiments whereby the sense of application (or phase) of the RF pulses is altered on repeating the experiment to eliminate spectral artefacts. Exorcyle takes its name from the fact that it is used to remove 'phantom' and 'ghost' peaks. For the technique see J. Magn. Reson., (1977), 27, pg 511. [CHMO]

Hadamard-encoded nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: Hadamard NMR spectroscopy
alternative label: Hadamard encoded NMR
alternative label: Hadamard nuclear magnetic resonance spectroscopy
alternative label: Hadamard-encoded NMR
definition: An NMR experiment in which multiple frequencies in an NMR spectrum are excited simultaneously over a broad frequency range using polychromatic pulses. [CHMO]

wideband, uniform rate and smooth truncation pulse
type: Class
subclass of: AFP_0001927
alternative label: WURST
alternative label: WURST pulse
alternative label: wideband, uniform rate and smooth truncation
definition: An adiabatic shaped pulse incorporating a linear sweep through a frequency range used for selective inversion of spin state populations over wide ranges. For the pulse see J. Magn. Reson., Ser. A, (1995), 115, pg 273. [CHMO]

globally optimized alternating phase rectangular pulse
type: Class
subclass of: composite pulse decoupling sequence
alternative label: GARP
alternative label: GARP pulse sequence
alternative label: GARP sequence
alternative label: globally-optimized alternating phase rectangular pulse
definition: A sequence of composite pulses designed to remove signal splitting due to heteronuclear J-couplings in multinuclear liquid NMR experiments. For the pulse sequence see J. Magn. Reson., (1985), 64, pg 547. [CHMO]

nuclear magnetic resonance diffusometry
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: NMR diffusometry
definition: Any type of NMR spectroscopy used to measure diffusion coefficients. [CHMO]

three-dimensional nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: 3D NMR
alternative label: 3D NMR spectroscopy
alternative label: 3D-NMR
alternative label: 3D-NMR spectroscopy
alternative label: three-dimensional (3D) NMR
alternative label: three-dimensional NMR
alternative label: three-dimensional NMR spectroscopy
definition: Any type of nuclear magnetic resonance spectroscopy in which three independent frequency dimensions are employed for the correlation and dispersal of signals (by employing two magnetization transfer steps). Each signal is described by three frequencies, thus effecting the distribution of signals within a cube. [CHMO]

Malcolm Levitt pulse sequence
type: Class
subclass of: composite pulse decoupling sequence
alternative label: MLEV
alternative label: MLEV pulse sequence
alternative label: MLEV sequence
definition: A sequence of composite pulses designed to remove signal splitting due to heteronuclear J-couplings in multinuclear liquid NMR experiments. Also used to allow transfer of magnetization between nuclei (by making the spins precess with at the same chemical shift and thus enjoy strong coupling - isotropic mixing). For the pulse sequence see J. Magn. Reson., (1981), 43, pg 502. [CHMO]

quadrupole Carr-Purcell-Meiboom-Gill experiment
type: Class
subclass of: AFP_0000759
alternative label: QCPMG experiment
definition: An NMR experiment used to measure spin-spin (T2) relaxation times of quadropolar nucei by acquiring multiple spin echos with the intensity decay of the echos proportional to T2. In the solid state, this is also used to enhance sensitivity of low gyromagnetic ratio nuclei by collapsing the intensity of the 'full' spectrum into discrete 'spikelets'/peaks. The intensities of the peaks vary according to T2 and the envelope described by these peaks represents the full, static spectrum. [CHMO]

triple-resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: backbone assignment experiment
alternative label: triple resonance NMR
alternative label: triple resonance NMR spectroscopy
alternative label: triple resonance nuclear magnetic resonance spectroscopy
alternative label: triple resonance nuclear magnetic spectroscopy
alternative label: triple resonance spectroscopy
alternative label: triple-resonance NMR
definition: A type of NMR experiment in which excitation of the spin states of three different types of nuclei (1H, 13C and 15N) is employed. [CHMO]

heteronuclear Hartmann Hahn pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: HEHAHA
alternative label: HEHAHA pulse sequence
alternative label: HEHAHA sequence
alternative label: heteronuclear Hartman-Hahn pulse sequence
alternative label: heteronuclear Hartman-Hahn sequence
alternative label: heteronuclear Hartmann Hahn
definition: An NMR pulse sequence used to transfer magnetization between protons and covalently bound (spin active) heteronuclei via isotropic mixing of their magnetization. Used to e.g. enhance the NMR signal of heteronuclei or to correlate chemical shifts of protons with heteronuclei. For the pulse sequence see J. Magn. Reson., (1991), 91, pg 444. [CHMO]

Burum, Linder, Ernst windowless pulse sequence
type: Class
subclass of: magic angle spinning decoupling pulse sequence
alternative label: BLEW
alternative label: BLEW pulse sequence
alternative label: BLEW sequence
alternative label: Burum-Linder-Ernst windowless pulse sequence
alternative label: Burum-Linder-Ernst windowless sequence
definition: A sequence of pulses used in magic angle spinning NMR to remove the effect of homonuclear dipolar couplings. A train/sequence of pulses is used to cyclically manipulate the signal whilst stroboscopic sampling ensures the effects of coupling are unobserved. For the pulse sequence see J. Magn. Reson., (1981), 44, pg 173. [CHMO]

X half filter
type: Class
subclass of: AFP_0000759
alternative label: X half-filter
definition: A technique used in 2D NMR of isotopically enriched samples (usually 13C/15N) to remove signals of protons which are not bound to a particular isotope from one of the two domains of the experiment. For the technique see J. Magn. Reson., (1986), 70, pg 500. [CHMO]

water suppression through gradient tailored excitation
type: Class
subclass of: solvent suppression pulse sequence
alternative label: WATERGATE
alternative label: WATERGATE pulse sequence
alternative label: WATERGATE sequence
definition: A pulse cluster used for solvent (water) suppression. The solvent resonances are selectively excited and pulsed field gradients used to destroy the signal. For the pulse sequence see J. Biomol. NMR, (1992), 2, pg 661. [CHMO]

HCANNH
type: Class
subclass of: triple-resonance spectroscopy
alternative label: HCANNH experiment
definition: A triple-resonance NMR experiment used to determine the chemical shifts of nuclei in a (isotopically enriched) protein. The chemical shift of the (backbone) amide proton is correlated with the chemical shift of the covalently bound nitrogen and with the alpha-carbon and proton of the same residue. The experiment name describes the path taken by the magnetization during the experiment. [CHMO]

gas-phase nuclear magnetic resonance spectroscopy
type: Class
subclass of: AFP_0000326
alternative label: gas phase NMR
alternative label: gas phase nuclear magnetic resonance spectroscopy
definition: A type of spectroscopy in the gas phase where the energy states of spin-active nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. [CHMO]

four-dimensional nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: 4D NMR
alternative label: 4D-NMR
alternative label: four-dimensional NMR
definition: Any type of nuclear magnetic resonance spectroscopy in which four independent frequency dimensions are employed for the correlation and dispersal of signals (by employing three magnetization transfer steps). Each signal is described by four frequencies, thus effecting the distribution of signals within an axis of cubes. [CHMO]

multiple quantum filter
type: Class
subclass of: AFP_0000759
alternative label: MQF
definition: An NMR technique used to edit the NMR response from a sample by selecting particular spin systems of interest according to the number of nuclei present within them. Usually achieved by appropriate cycling of the phase (direction of application) of the pulses in an experiment and of the receiver. [CHMO]

high-resolution magic angle spinning
type: Class
subclass of: magic angle spinning
alternative label: HR MAS
alternative label: HR-MAS
alternative label: HR-MAS NMR spectroscopy
alternative label: HR/MAS
alternative label: HRMAS
alternative label: HRMAS NMR spectroscopy
alternative label: high resolution magic-angle spinning
definition: A type of NMR spectroscopy using a solid sample and a high resolution magnetic susceptibility matching probe. Anisotropic interactions between nuclei, which are usually averaged by Brownian motion in liquid samples, cause significant line broadening in solid state NMR, but can be averaged to zero by spinning the sample very rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field). [CHMO]

heteronuclear single quantum coherence total correlation spectroscopy
type: Class
subclass of: heteronuclear three-dimensional nuclear magnetic resonance spectroscopy
alternative label: 3D HSQC-TOCSY
alternative label: 3D TOCSY-HSQC
alternative label: HSQC-TOCSY
alternative label: TOCSY-HSQC
definition: A type of heteronuclear three-dimensional NMR experiment in which the proton signals of a 2D TOCSY spectrum are dispersed along a third frequency axis according to the chemical shift of their covalently bound heteronuclei. [CHMO]

HNCAHA
type: Class
subclass of: triple-resonance spectroscopy
alternative label: HNCAHA experiment
definition: A triple-resonance NMR experiment used to determine the chemical shifts of nuclei in a (isotopically enriched) protein. The chemical shift of the (backbone) amide proton is correlated with the chemical shift of the covalently bound nitrogen and the alpha-carbon and proton of the same residue. The experiment name describes the path taken by the magnetization during the experiment. [CHMO]

frequency-switched Lee-Goldberg cross polarization
type: Class
subclass of: polarization inversion and spin exchange at the magic angle
alternative label: FSLG-CP
alternative label: frequency switched Lee-Goldberg cross polarization
definition: A magic angle spinning NMR dipolar recoupling technique used to determine dipolar couplings between 1H and 13C nuclei. A FSLG sequence is used to remove homonuclear couplings (by spin-locking the 1H nuclei) and polarization transfer from the protons to the 13C via dipolar coupling manifests as a splitting of the detected 13C signal. [CHMO]

decoupling pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
definition: An NMR pulse sequence that decouples nuclei i.e. removes the effects of dipolar coupling or J-coupling from the spectrum. [CHMO]

water suppression
type: Class
subclass of: AFP_0000759
change note: 2024-09-11 Replaced unlicensed definition with an Allotrope written one.
definition: Water suppression is a nuclear magnetic resonance assay used to suppress the signal from water. [Allotrope]

satellite transition magic angle spinning
type: Class
subclass of: magic angle spinning
alternative label: STMAS
alternative label: satellite-transition MAS
alternative label: satellite-transition magic angle spinning
alternative label: satellite-transition magic-angle spinning
definition: An NMR experiment where the selective excitation of central and satellite transitions during magic angle spinning is used for recording high-resolution NMR spectra of quadrupolar nuclei in solids. Central transitions are detected first, followed by satellite transitions. [CHMO]

diffusion-ordered spectroscopy-correlation spectroscopy
type: Class
subclass of: three-dimensional diffusion-ordered spectroscopy
alternative label: 3D COSY-DOSY
alternative label: 3D DOSY-COSY
alternative label: COSY-DOSY
alternative label: DOSY-COSY
alternative label: correlation spectroscopy-diffusion-ordered spectroscopy
definition: A type of three-dimensional NMR experiment in which the signals of a 2D COSY spectrum are dispersed along a third frequency axis according to diffusion coefficient. [CHMO]

Mansfield, Rhim, Elleman, Vaughn pulse sequence
type: Class
subclass of: magic angle spinning decoupling pulse sequence
alternative label: MREV
alternative label: MREV pulse sequence
alternative label: MREV sequence
alternative label: Mansfield Rhim Elleman Vaughn sequence
alternative label: Mansfield, Rhim, Elleman, Vaughn sequence
alternative label: Mansfield-Rhim-Elleman-Vaughn pulse sequence
alternative label: Mansfield-Rhim-Elleman-Vaughn sequence
definition: A pulse sequence used in magic angle spinning NMR to remove the effects of homonuclear dipolar coupling. For the pulse sequence see J. Chem. Phys., (1973), 59, pg 3740. [CHMO]

only para-hydrogen spectroscopy correlation spectroscopy
type: Class
subclass of: only para-hydrogen spectroscopy
alternative label: OPSY-COSY
definition: A type of homonuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between nuclei which are J-coupled (usually <= 3 bonds apart). Thermal signals in the resulting spectra are then removed, whilst keeping the signals from para-hydrogen-derived protons intact. [CHMO]

pulsed-field gradient nuclear magnetic spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: PFG-NMR
definition: A type of NMR spectroscopy where a spatially inhomogeneous magnetic field with a defined gradient is used, either to select a particular signal or to render unwanted signals undetectable. [CHMO]

high-field nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: high field NMR
alternative label: high-field NMR
definition: A type of spectroscopy where the energy states of spin-active nuclei placed in a static (>300 MHz) magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them. [CHMO]

nuclear Overhauser enhancement spectroscopy-correlation spectroscopy
type: Class
subclass of: homonuclear three-dimensional nuclear magnetic resonance spectroscopy
alternative label: 3D NOESY-COSY
alternative label: 3D-NOESY-COSY
alternative label: NOESY-COSY
definition: A type of homonuclear three-dimensional NMR experiment in which correlations are seen between nuclei that are spatially proximate within a molecule (<= 6 Angstrom apart). These signals are then correlated with those protons to which they are J-coupled (usually <= 3 bonds apart). [CHMO]

FID truncation
type: Class
subclass of: nuclear magnetic resonance spectroscopy data processing
definition: Truncation of the FID recorded either by insufficient acquisition time or by post acquisition processing. [Allotrope]

first order phase correction
type: Class
subclass of: phase correction
definition: The application of a Phase Correction algorithm to a Fourier transform NMR spectra such that it is optimised to accommodate for the frequency independent time delay between excitation (the RF pulse) and relaxation (acquiring the FID) to give maximum values of the FID Fourier Transform complex number set. [Allotrope]

double-quantum-filtered correlation spectroscopy
type: Class
subclass of: correlation spectroscopy
alternative label: DQF-COSY
alternative label: double quantum filtered COSY
alternative label: double quantum filtered correlation spectroscopy
alternative label: double-quantum-filtered COSY
definition: A type of homonuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between nuclei which are J-coupled (usually <= 3 bonds apart). The response is edited by selecting only two-spin coupled systems, usually achieved by appropriate cycling of the phase (direction of application) of the pulses in the experiment. [CHMO]

manual phase correction
type: Class
subclass of: phase correction
definition: The application of a mathematical operation to both the real and imaginary parts of the complex numbers represented by the FID recorded as the sample magnetisation vector relaxes from its excited state vector back to its equilibrium bulk magnetisation population as adjusted by the user set values. [Allotrope]

HNCO
type: Class
subclass of: triple-resonance spectroscopy
alternative label: HNCO experiment
definition: A triple-resonance NMR experiment used in to determine the chemical shifts of nuclei in a (isotopically enriched) protein. The chemical shift of the (backbone) amide proton is correlated with the chemical shift of the covalently bound nitrogen and the carbonyl carbon of the preceding residue. [CHMO]

delays alternating with nutation for tailored excitation
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: DANTE
alternative label: DANTE pulse sequence
alternative label: DANTE sequence
change note: 2024-09-11 Removed [Amgen] attribution as this is purely a [CHMO] term.
definition: A pulse sequence used to selectively excite a frequency range by applying a series of very short pulses to manipulate, or nutate, the magnetization vectors of the desired spins, interspersed with delays which cause the off-resonance magnetisation not to be excited. For the pulse see J. Magn. Reson., (1978), 29, pg 433. [CHMO]

two-dimensional heteronuclear single quantum coherence-nuclear Overhauser effect spectroscopy
type: Class
subclass of: heteronuclear two-dimensional nuclear magnetic resonance spectroscopy
alternative label: 2D HSQC-NOESY
alternative label: 2D NOESY-HSQC
alternative label: two-dimensional heteronuclear single quantum coherence nuclear Overhauser effect spectroscopy
definition: A 2D NMR experiment which correlates the chemical shifts of spatially proximate protons with the chemical shifts of all (of one type of) their covalently bound heteronuclei. [CHMO]

spin counting experiment
type: Class
subclass of: AFP_0000759
definition: An NMR experiment which measures the variation in amplitude of signals from dipolar-coupled nuclei over time, yielding information about the number of coupled nuclei in the system. [CHMO]

two-dimensional nuclear Overhauser enhancement spectroscopy
type: Class
subclass of: nuclear Overhauser enhancement spectroscopy
alternative label: 2D NOESY
alternative label: 2D NOESY NMR
alternative label: 2D homonuclear NOESY
alternative label: 2D nOesy
alternative label: 2D nuclear Overhauser enhancement spectroscopy
alternative label: 2D-NOESY
alternative label: 2D-nOesy
definition: A type of homonuclear NMR spectroscopy where a second frequency dimension is employed, based on the nuclear Overhauser enhancement effect in which correlations are seen between nuclei that are spatially proximate within a molecule (<=6 Angstrom apart). [CHMO]

nuclear magnetic resonance decoupling
type: Class
subclass of: AFP_0000759
source: https://en.wikipedia.org/wiki/Nuclear_magnetic_resonance_decoupling
alternative label: NMR decoupling
change note: 2024-09-11 Replaced [nmrML] attribution with [Wikipedia] as this is the correct source.
definition: Nuclear magnetic resonance decoupling (NMR decoupling for short) is a special method used in nuclear magnetic resonance (NMR) spectroscopy where a sample to be analyzed is irradiated at a certain frequency or frequency range to eliminate fully or partially the effect of coupling between certain nuclei. NMR coupling refers to the effect of nuclei on each other in atoms within a couple of bonds distance of each other in molecules. This effect causes NMR signals in a spectrum to be split into multiple peaks which are up to several hertz (or tens or hundreds of hertz) frequency from each other. Decoupling fully or partially eliminates splitting of the signal between the nuclei irradiated and other nuclei such as the nuclei being analyzed in a certain spectrum. NMR spectroscopy and sometimes decoupling can help determine structures of chemical compounds. [Wikipedia]

para-hydrogen induced polarization enhanced nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: PHIP NMR
alternative label: PHIP-NMR
alternative label: PHIP-enhanced NMR
alternative label: para-hydrogen induced polarization enhanced NMR spectroscopy
definition: A type of spectroscopy where the energy states of protons derived from para-hydrogen (dihydrogen with an antisymmetric nuclear spin arrangement) placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them. The non-Boltzmann spin population generated by para-hydrogen-derived protons gives rise to signal enhancement in the spectra, facilitating the detection of species present at low concentration. [CHMO]

multiple-quantum excitation in combination with magic angle spinning
type: Class
subclass of: magic angle spinning
alternative label: MQMAS
alternative label: MQMAS NMR
alternative label: multiple-quantum MAS
alternative label: multiple-quantum excitation in combination with magic-angle spinning
definition: An NMR experiment used for half-integer quadrupolar nuclei, involving transitions between non-consecutive energy levels during the excitation of the spin system by multiple-quantum excitation pulses. [CHMO]

distortionless enhancement with polarization transfer
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: DEPT
alternative label: DEPT NMR
alternative label: distortionless enhancement by polarization transfer
definition: A type of spectroscopy where the energy states of 13C nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them.The 13C NMR signals are enhanced by transferring 1H magnetization to 13C nuclei and the phase of the signals reflects the multiplicity i.e. CH, CH2 or CH3). Separate methyl, methylene and methine spectra may be obtained. [CHMO]

Hadamard-encoded total correlation spectroscopy
type: Class
subclass of: total correlation spectroscopy
alternative label: 2D Hadamard encoded TOCSY
alternative label: Hadamard TOCSY
alternative label: Hadamard-TOCSY
definition: A type of homonuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between all nuclei of a spin-system. All of the resonances in the spin system are excited by selecting only one line for excitation and the final spectrum consists of a series of 1D sub-spectra, each representing one spin system. [CHMO]

inverse satellite transition magic angle spinning
type: Class
subclass of: satellite transition magic angle spinning
alternative label: I-STMAS
alternative label: ISTMAS
alternative label: inverse-STMAS
definition: An NMR experiment where the selective excitation of central and satellite transitions during magic angle spinning is used for recording high-resolution NMR spectra of quadrupolar nuclei in solids. Satellite transitions are detected first, followed by central transitions. [CHMO]

composite pulse decoupling sequence
type: Class
subclass of: decoupling pulse sequence
alternative label: CPD
definition: An NMR pulse sequence, employing composite pulses, which decouples nuclei i.e. removes the effects of (usually) J-coupling (line splitting) from the spectrum. [CHMO]

variable angle spinning
type: Class
subclass of: AFP_0000759
alternative label: VAS
alternative label: variable-angle spinning
definition: A technique used in solid-state NMR experiments to achieve the controlled reintroduction of dipolar couplings by varying the angle at which the sample is spun relative to the applied magnetic field. [CHMO]

double quantum filter
type: Class
subclass of: multiple quantum filter
alternative label: DQF
definition: An NMR technique used to edit the NMR response from a sample by selecting only two-spin coupled systems, usually achieved by appropriate cycling of the phase (direction of application) of the pulses in an experiment and of the receiver. [CHMO]

separated-local-field nuclear magnetic resonance spectroscopy
type: Class
subclass of: two-dimensional nuclear magnetic resonance spectroscopy
alternative label: 2D SLF
alternative label: 2D SLF NMR
alternative label: 2D separated local field NMR
alternative label: 2D-SLF
alternative label: 2D-SLF NMR
alternative label: SLF NMR
alternative label: SLF spectroscopy
alternative label: separate local field NMR
alternative label: separate-local-field NMR
alternative label: separated local field (SLF) NMR
alternative label: separated local field NMR
alternative label: separated local field spectroscopy
alternative label: separated-local field (SLF) NMR
alternative label: separated-local field NMR
alternative label: separated-local-field spectroscopy
definition: A two-dimensional NMR experiment which exploits the differential dipolar couplings which nuclei exhibit to their neighboring protons within local magnetic fields. The experiment consist of two time intervals: during the first time period the dipolar couplings are encoded in the NMR signal, while in the detection period the signals of different nuclei are separated on the basis of their differences in chemical shift. [CHMO]

nuclear magnetic resonance spectroscopy data processing
type: Class
subclass of: AFP_0003598
definition: Data processing on nuclear magnetic resonance spectroscopy spectra or nuclear magnetic resonance spectroscopy FID. [Allotrope]

total correlation spectroscopy-nuclear Overhauser enhancement spectroscopy
type: Class
subclass of: homonuclear three-dimensional nuclear magnetic resonance spectroscopy
alternative label: 3D TOCSY-NOESY
alternative label: 3D-TOCSY-NOESY
alternative label: TOCSY-NOESY
definition: A type of homonuclear three-dimensional NMR experiment spectroscopy which reveals correlations between all nuclei of a spin-system. These signals are then correlated to nuclei that are spatially proximate within the molecule (<= 6 Angstrom apart). [CHMO]

cyclically ordered phase sequence
type: Class
subclass of: phase cycle
alternative label: CYCLOPS
definition: A phase cycle technique used in FT NMR experiments whereby the sense of application (or phase) of the RF pulses is altered on repeating the experiment such that addition of the resulting signals results in increased intensity for the signals of interest and more effective noise reduction. For the technique see Progr. NMR Spectr., (1978), 12, pg 41. [CHMO]

diffusion-ordered spectroscopy-total correlation spectroscopy
type: Class
subclass of: three-dimensional diffusion-ordered spectroscopy
alternative label: 3D DOSY-TOCSY
alternative label: 3D TOCSY-DOSY
alternative label: DOSY-TOCSY
alternative label: TOCSY-DOSY
alternative label: total correlation spectroscopy-diffusion-ordered spectroscopy
definition: A type of three-dimensional NMR experiment in which the signals of a 2D TOCSY spectrum are dispersed along a third frequency axis according to diffusion coefficient. [CHMO]

transverse relaxation optimised spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: TROSY
alternative label: TROSY NMR
alternative label: transverse relaxation optimized spectroscopy
definition: A type of NMR experiment employed for protein samples in which relaxation mechanisms are optimised in order to suppress transverse relaxation times (T2) and deliver only the sharpest signal present in a multiplet. [CHMO]

heteronuclear single quantum coherence-nuclear Overhauser spectroscopy
type: Class
subclass of: heteronuclear three-dimensional nuclear magnetic resonance spectroscopy
alternative label: 3D HSQC-NOESY
definition: A 3D NMR experiment in which the chemical shifts of protons are correlated with the chemical shifts their covalently-bound heteronuclei and with the shifts of spatially proximate protons (<6 Angstrom). [CHMO]

variable-temperature nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: VT NMR
alternative label: VT-NMR
alternative label: variable temperature NMR
alternative label: variable temperature nuclear magnetic resonance spectroscopy
alternative label: variable-temperature NMR
definition: A type of spectroscopy where the response of a nucleus with non-zero spin to a perturbing magnetic field is detected at temperatures above or below the ambient probe temperature. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them. [CHMO]

solvent suppression pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
definition: An NMR pulse sequence that is used to suppress or remove the solvent signal. [CHMO]

four-dimensional HCCH-total correlation spectroscopy
type: Class
subclass of: triple-resonance spectroscopy
alternative label: 4D HCCH-TOCSY
definition: A 4D triple-resonance NMR experiment used to determine the chemical shifts of nuclei in a (isotopically enriched) protein. The chemical shifts of the protons of a sidechain are correlated with their covalently bound 13C nuclei and with the other protons of the side-chain. [CHMO]

Carr-Purcell-Meiboom-Gill pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: CPMG
alternative label: CPMG pulse sequence
alternative label: CPMG sequence
alternative label: Carr, Purcell,Meiboom,Gill pulse sequence
alternative label: Carr-Purcell Meiboom-Gill pulse sequence
definition: A pulse sequence which is applied during nuclear magnetic resonance spectroscopy to measure spin-spin (T2) relaxation times. For the pulse sequence see Rev. Sci. Inst., (1958), 29, pg 688. [CHMO]

continuous-wave nuclear magnetic resonance spectroscopy
type: Class
subclass of: AFP_0000326
alternative label: NMR absorption spectroscopy
alternative label: c.w. NMR
alternative label: continuous wave nuclear magnetic resonance spectrometry
alternative label: continuous wave nuclear magnetic resonance spectroscopy
alternative label: cw-NMR
definition: A type of spectroscopy where the energy states of spin-active nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Spectra are obtained by scanning a range of radio frequencies. [CHMO]

five-quantum excitation in combination with magic angle spinning
type: Class
subclass of: multiple-quantum excitation in combination with magic angle spinning
alternative label: 5QMAS
alternative label: 5QMAS NMR
alternative label: five-quantum MAS
alternative label: five-quantum excitation in combination with magic-angle spinning
definition: An NMR experiment used for 5/2-spin quadrupolar nuclei, involving transitions between non-consecutive energy levels during the excitation of the spin system by the first RF pulse. [CHMO]

magic angle spinning decoupling pulse sequence
type: Class
subclass of: decoupling pulse sequence
definition: An NMR pulse sequence, used in magic angle spinning, that decouples nuclei i.e. removes the effects of (usually) J-coupling (line splitting) from the spectrum. [CHMO]

inversion recovery total correlation spectroscopy
type: Class
subclass of: total correlation spectroscopy
alternative label: IR-TOCSY
alternative label: inversion recovery TOCSY
alternative label: inversion-recovery TOCSY
definition: A two-dimensional NMR experiment which shows correlations between all the nuclei of a spin system and also allows determination of T1 relaxation rates. [CHMO]

pulsed field gradient
type: Class
subclass of: AFP_0000759
alternative label: PFG
alternative label: ge-NMR
alternative label: gradient NMR
alternative label: gradient-enhanced NMR
alternative label: gradient-selected NMR
alternative label: gs-NMR
alternative label: pulsed-field gradient
definition: A tool employed in NMR experiments; spatially inhomogeneous magnetic fields applied with a defined gradient. Used to either select a particular signal or to render unwanted signals undetectable. [CHMO]

polarization inversion and spin exchange at the magic angle
type: Class
subclass of: magic angle spinning
alternative label: PISEMA
alternative label: dipolar recoupling distance experiment
alternative label: dipolar recoupling experiment
definition: Magic angle spinning NMR experiments in which dipolar coupling is reintroduced to obtain information on the proximity of nuclei within the sample. [CHMO]

cross-polarization magic angle spinning
type: Class
subclass of: magic angle spinning
alternative label: CP-MAS
alternative label: CP-MAS NMR
alternative label: CP/MAS
alternative label: CP/MAS NMR
alternative label: CPMAS
alternative label: CPMAS NMR
alternative label: cross polarization magic angle spinning
alternative label: cross polarization magic angle spinning nuclear magnetic resonance spectroscopy
alternative label: cross-polarization magic angle spinning nuclear magnetic resonance spectroscopy
definition: A type of NMR spectroscopy using a solid sample. Anisotropic interactions between nuclei, which are usually averaged by Brownian motion in liquid samples, cause significant line broadening in solid state NMR, but can be reduced to zero by spinning the sample very rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field). Cross polarization is used to enhance the signal from weakly coupled nuclei. [CHMO]

triple-quantum excitation in combination with magic angle spinning
type: Class
subclass of: multiple-quantum excitation in combination with magic angle spinning
alternative label: 3QMAS
alternative label: 3QMAS NMR
alternative label: TQMAS
alternative label: TQMAS-NMR
alternative label: triple-quantum MAS
alternative label: triple-quantum excitation in combination with magic-angle spinning
definition: An NMR experiment used for 3/2-spin quadrupolar nuclei, involving transitions between non-consecutive energy levels during the excitation of the spin system by triple-quantum excitation pulses. [CHMO]

incredible natural abundance double quantum transfer experiment
type: Class
subclass of: two-dimensional nuclear magnetic resonance spectroscopy
alternative label: 2D INADEQUATE
alternative label: 2D INADEQUATE NMR
alternative label: INADEQUATE
alternative label: INADEQUATE NMR
definition: A 2D NMR technique which correlates (commonly one-bond) J-coupled homonuclei. In one dimension, the signals appear at the chemical shift of a particular nucleus and in the other dimension, at a position which is the sum of the frequencies of that nucleus and its J-coupled partner. [CHMO]

57Fe electron nuclear double resonance spectroscopy
type: Class
subclass of: pulsed electron nuclear double resonance spectroscopy
alternative label: 57Fe ENDOR
alternative label: 57Fe ENDOR spectroscopy
alternative label: iron-57 ENDOR
alternative label: iron-57 ENDOR spectroscopy
definition: A type of spectroscopy where a microwave frequency pulse is used to saturate the electron resonance transitions in the 57Fe nuclei of a sample, and a radio frequency pulse is used excite a nuclear transition. [CHMO]

one-dimensional 1H nuclear magnetic resonance spectroscopy
type: Class
subclass of: one-dimensional nuclear magnetic resonance spectroscopy
alternative label: 1D 1H NMR
alternative label: 1D proton NMR
change note: 2024-09-11 Removed [Amgen] attribution as this is a [CHMO] term.
definition: A type of spectroscopy where the energy states of 1H nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them, and the spectrum is obtained by plotting chemical shift vs. frequency. 1D 1H NMR usually uses one pulse (90 or 30 degree pulse) for excitation. [CHMO]

deuterium-decoupled nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: 2H decoupled NMR
alternative label: 2H-decoupled NMR
alternative label: deuterium-decoupled NMR
alternative label: deuterium-decoupled NMR spectroscopy
definition: A type of NMR spectroscopy where (J/scalar) couplings to 2H nuclei are cancelled by applying radio frequency radiation to saturate or otherwise manipulate the 2H spins such that no evolution of the coupling occurs. [CHMO]

HCC(CO)NNH
type: Class
subclass of: triple-resonance spectroscopy
alternative label: HCC(CO)NNH experiment
definition: A triple-resonance NMR experiment used to determine the chemical shifts of nuclei in a (isotopically enriched) protein. The chemical shift of the (backbone) amide proton is correlated with the chemical shift of the covalently bound nitrogen and with both the alpha- and beta-carbons and protons of the preceding residue. The experiment name describes the path taken by the magnetization during the experiment. [CHMO]

nuclear Overhauser enhancement spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: 2D EXSY
alternative label: 2D exchange spectroscopy
alternative label: EXSY
alternative label: NOE experiments
alternative label: NOESY
alternative label: NOESY NMR
alternative label: NOEsy
alternative label: exchange spectrometry
alternative label: exchange spectroscopy
alternative label: nOesy
alternative label: nuclear Overhauser effect spectrometry
alternative label: nuclear Overhauser effect spectroscopy
alternative label: nuclear Overhauser enhancement spectrometry
definition: A type of homonuclear NMR spectroscopy based on the nuclear Overhauser enhancement effect in which correlations are seen between nuclei that are spatially proximate within a molecule (<= 6 Angstrom apart). [CHMO]

paramagnetic relaxation enhancement
type: Class
subclass of: AFP_0000759
alternative label: PRE
alternative label: paramagnetic relaxation enhancements
definition: An NMR technique whereby paramagnetic ions are introduced to a sample which cause enhanced relaxation of the spins in proximity of the paramagnetic spin label, giving long-range (up to 24 Angstrom) structural information. Also used in binding studies, allowing identification of the atoms involved in binding. [CHMO]

double pulsed field gradient spin echo pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: DPFGSE
alternative label: DPFGSE excitation
alternative label: DPFGSE pulse sequence
alternative label: DPFGSE sequence
alternative label: double pulsed field gradient spin echo
alternative label: double pulsed field gradient spin-echo
alternative label: double pulsed field gradient spin-echo pulse sequence
definition: An NMR pulse sequence in which pulsed field gradients are applied to a doubled spin echo sequence to cleanly and precisely excite particular resonances. For the pulse sequence see J. Magn. Reson. A, (1995), 112, pg 275. [CHMO]

total correlation spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: HOHAHA spectrometry
alternative label: HOHAHA spectroscopy
alternative label: TOCSY
alternative label: homonuclear Hartmann Hahn spectroscopy
alternative label: homonuclear Hartmann,Hahn spectroscopy
alternative label: homonuclear Hartmann-Hahn spectroscopy
alternative label: total correlated spectroscopy
alternative label: total correlation spectrometry
definition: A type of homonuclear NMR spectroscopy which reveal correlations between all nuclei of a spin-system. [CHMO]

flip-back nuclear Overhauser enhancement spectroscopy
type: Class
subclass of: two-dimensional nuclear Overhauser enhancement spectroscopy
alternative label: fb-NOESY
alternative label: fb-NOESY NMR
alternative label: fb-nOesy
alternative label: flip-back nuclear Overhauser effect spectrometry
alternative label: flip-back nuclear Overhauser effect spectroscopy
alternative label: flip-back nuclear Overhauser enhancement spectrometry
definition: A type of heteronuclear two-dimensional NMR spectroscopy incorporating a water flip-back sequence, based on the nuclear Overhauser enhancement effect in which correlations are seen between nuclei that are spatially proximate within a molecule (<= 6 Angstrom apart). [CHMO]

R-type recoupling proton detected separated local field spectroscopy
type: Class
subclass of: proton detected separated local field spectroscopy
subclass of: magic angle spinning
alternative label: PDLF with R-type recoupling
alternative label: R-PDLF
alternative label: R-type recoupling proton detected local field spectroscopy
alternative label: proton-deteced separated local field spectroscopy with R-type recoupling
definition: A magic-angle spinning NMR experiment to measure dipolar couplings. Dipolar couplings are reintroduced by synchronising RF pulses with the rotation of the rotor. Spectral simplification occurs via the proton detected separated local field protocol where 1H-1H interactions are decoupled and proton magnetization is passed through 13C nuclei present at natural abundance. [CHMO]

homonuclear three-dimensional nuclear magnetic resonance spectroscopy
type: Class
subclass of: three-dimensional nuclear magnetic resonance spectroscopy
alternative label: homonuclear 3D NMR
definition: Any type of nuclear magnetic resonance spectroscopy in which three independent frequency dimensions are employed for the correlation and dispersal of signals. Each signal is described by three frequencies, all arising from the same type of nucleus, thus effecting the distribution of signals within a cube. [CHMO]

AFP_0001233
type: Class
subclass of: AFP_0001211
alternative label: PDMR

water elimination Fourier transform
type: Class
subclass of: solvent suppression pulse sequence
alternative label: WEFT
alternative label: WEFT pulse sequence
alternative label: WEFT sequence
alternative label: water-elimination Fourier transform
definition: A pulse cluster used to suppress solvent (water) signals exploiting the differing relaxation properties of solvent and sample. Resonances are inverted and the subsequent recovery period is chosen such that the solvent signal is at a null point when the signal is detected. For the pulse sequence see J. Chem. Phys., (1972), 56, pg 3182. [CHMO]

correlation spectroscopy
type: Class
subclass of: two-dimensional nuclear magnetic resonance spectroscopy
alternative label: COSY
alternative label: correlated spectrometry
alternative label: correlated spectroscopy
alternative label: correlation spectrometry
definition: A type of homonuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between nuclei which are J-coupled (usually <= 3 bonds apart). [CHMO]

states-time proportional phase incrementation
type: Class
subclass of: AFP_0000759
alternative label: states-TPPI
alternative label: states-TPPI acquisition
definition: A technique used in multidimensional NMR experiments to achieve frequency discrimination of the signals in the additional dimensions. [CHMO]

specific proton decoupling
type: Class
subclass of: homonuclear decoupling
alternative label: band selective decoupling
alternative label: narrow band decoupling
alternative label: specific band decoupling
alternative label: specific decoupling
definition: A specified narrow frequency band associated with a specific nuclei of a specified isotope is selectively irradiated with a weak RF pulse. [Allotrope]

nuclear Overhauser enhancement spectroscopy-total correlation spectroscopy
type: Class
subclass of: homonuclear three-dimensional nuclear magnetic resonance spectroscopy
alternative label: 3D NOESY-TOCSY
alternative label: 3D-NOESY-TOCSY
alternative label: NOESY-TOCSY
definition: A type of homonuclear NMR spectroscopy which reveal correlations between all nuclei of a spin-system. These signals are then correlated to nuclei that are spatially proximate within the molecule (<= 6 Angstrom apart). [CHMO]

one-dimensional nuclear Overhauser enhancement spectroscopy
type: Class
subclass of: nuclear Overhauser enhancement spectroscopy
alternative label: 1D NOESY
alternative label: 1D nOesy
alternative label: 1D nuclear Overhauser enhancement spectroscopy
alternative label: 1D-NOESY
alternative label: 1D-nOesy
alternative label: NOESY NMR
definition: A type of homonuclear NMR spectroscopy where only one frequency dimension is employed, based on the nuclear Overhauser enhancement effect in which correlations are seen between nuclei that are spatially proximate within a molecule (<=6 Angstrom apart). [CHMO]

constant time method
type: Class
subclass of: AFP_0000759
alternative label: CT experiment
alternative label: CT method
alternative label: constant time experiment
definition: A technique used in 2D NMR whereby the chemical shift frequency modulation of the FIDs necessary to interrogate the second dimension is achieved by moving the position of a RF pulse within a fixed time period on subsequent repeats of the experiment. [CHMO]

heteronuclear single quantum coherence
type: Class
subclass of: heteronuclear two-dimensional nuclear magnetic resonance spectroscopy
alternative label: HSQC
definition: A type of heteronuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between protons and the nuclei to which they are covalently bound. [CHMO]

heteronuclear two-dimensional nuclear magnetic resonance spectroscopy
type: Class
subclass of: two-dimensional nuclear magnetic resonance spectroscopy
alternative label: heteronuclear 2D NMR
definition: Any type of heteronuclear NMR spectroscopy where a second frequency dimension is employed. [CHMO]

AFP_0001349
type: Class
subclass of: AFP_0001211
alternative label: FDMR

time proportional phase incrementation
type: Class
subclass of: AFP_0000759
alternative label: TPPI
definition: A technique used in multidimensional NMR experiments to achieve frequency discrimination of the signals in the additional dimensions. [CHMO]

proton detected separated local field spectroscopy
type: Class
subclass of: separated-local-field nuclear magnetic resonance spectroscopy
alternative label: PDLF
alternative label: proton detected local field spectroscopy
alternative label: proton-detected SLF
alternative label: proton-detected separated local field spectroscopy
definition: An NMR experiment for the measurement of heteronuclear dipolar couplings. 1H-1H interactions are decoupled and proton magnetization is passed through 13C nuclei present at natural abundance to simplify a dipolarly coupled spectrum. [CHMO]

presaturation
type: Class
subclass of: AFP_0000759
definition: An NMR technique whereby particular resonances are saturated (their spin-state populations are equalised). Commonly used to suppress solvent signals. [CHMO]

chirped pulse
type: Class
subclass of: AFP_0001927
alternative label: CHIRP
alternative label: CHIRP pulse
alternative label: chirp pulse
definition: An adiabatic shaped pulse. The resonance frequency is swept through a defined RF range during application of the pulse. Allows excitation of a broader range of frequencies than the size of the RF field. For the pulse see J. Magn. Reson., Ser. A, (1993), 102, pg 293. [CHMO]

rotational-echo double-resonance spectroscopy
type: Class
subclass of: magic angle spinning
alternative label: REDOR
alternative label: rotational echo double resonance spectroscopy
alternative label: rotational echo double-resonance (REDOR) spectroscopy
definition: A magic angle spinning NMR experiment in which the evolution of dipolar couplings between nuclei is controlled by applying pulses at appropriate points in the rotational period, allowing the determination of the size of the coupling and, thus, yielding distance information. [CHMO]

spin echo pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: spin echo sequence
alternative label: spin-echo pulse sequence
alternative label: spin-echo sequence
definition: A pulse cluster used in NMR experiments which manipulates signals such that, at the end of the sequence, the effects of chemical shift differences have been compensated/removed. Used most simply to compensate for inhomogeneities in the magnetic field but delays in the sequence also permit various possible manipulations of the magnetization. For the pulse sequence see Phys. Rev., (1950), 80, pg 580. [CHMO]

paramagnetic signals enhancement
type: Class
subclass of: AFP_0000759
alternative label: PASE
alternative label: PASE NMR
alternative label: PAramagneticSignalsEnhancement
alternative label: paramagnetic signals enhancement NMR
alternative label: paramagneticsignalsenhancement
definition: A method for NMR spectra acquisition of paramagnetic proteins, based on the use of homonuclear broadband decoupling of the diamagnetic region. [CHMO]

spin diffusion experiment
type: Class
subclass of: AFP_0000759
definition: An NMR experiment which exploits the increased efficiency of energy (magnetization) transfer between nuclei via dipolar coupling in rigid or semi-rigid samples. The rate at which polarization is transferred between spins is measured giving information on the proximity and orientation of the interacting spins within the sample. [CHMO]

only para-hydrogen spectroscopy
type: Class
subclass of: pulsed-field gradient nuclear magnetic spectroscopy
alternative label: OPSY
alternative label: OPSY NMR
definition: An NMR experiment where pulsed field gradients are used to filter thermal signals from NMR spectra whilst leaving those derived from para-hydrogen-derived protons intact. [CHMO]

spectral referencing
type: Class
subclass of: nuclear magnetic resonance spectroscopy data processing
definition: Standardizing an NMR spectra setting the reference point to a known value. [Allotrope]
example: usually residual solvent protons in 1H NMR spectroscopy for example, or reference inserts e.g. TMS

satellite transition magic angle spinning with self-compensation for the magic angle misset
type: Class
subclass of: satellite transition magic angle spinning
alternative label: SCAM-STMAS
definition: An NMR experiment where the selective excitation of satellite transitions during magic angle spinning is used for recording high-resolution NMR spectra of quadrupolar nuclei in solids. In conventional magic angle spinning the spinning angle must be very accurate, but this technique can self-compensate magic-angle errors of up to (+/- 1.0 deg.). [CHMO]

total suppression of sidebands pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: TOSS
alternative label: TOSS pulse sequence
alternative label: TOSS sequence
definition: A pulse sequence used in magic angle spinning NMR experiments to remove additional signals resulting from spinning the sample too slowly to obtain a response composed solely of isotropic chemical shifts. [CHMO]

double quantum transitions for finding unresolved lines
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: DOUBTFUL
alternative label: DOUBTFUL pulse sequence
alternative label: DOUBTFUL sequence
definition: A pulse sequence used to selectively resolve the signals from two coupled nuclei, see J. Am. Chem. Soc., (1982), 104, pg 4286. [CHMO]

nuclear Overhauser enhancement spectroscopy with paramagnetic signals enhancement
type: Class
subclass of: nuclear Overhauser enhancement spectroscopy
alternative label: PASE NOESY
alternative label: PASE-NOE
alternative label: PASE-NOESY
definition: A type of homonuclear NMR spectroscopy based on the nuclear Overhauser enhancement effect in which correlations are seen between nuclei that are spatially proximate within a molecule (<= 6 Angstrom apart). Spectra recorded with suppression of the diamagnetic window by the PASE pulse sequence. [CHMO]

pulsed gradient non-linear spin echo nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed field-gradient spin echo nuclear magnetic resonance spectroscopy
alternative label: PGNE
alternative label: PGNE NMR
alternative label: PGNE-NMR
alternative label: pulsed gradient non-linear echo
alternative label: pulsed gradient nonlinear echo
alternative label: pulsed gradient nonlinear spin echo
definition: An NMR experiment used to measure small diffusion coefficients via the attenuation of signals occurring due to molecular diffusion during the application of pulsed field gradients. [CHMO]

heteronuclear multiple quantum coherence
type: Class
subclass of: heteronuclear two-dimensional nuclear magnetic resonance spectroscopy
alternative label: HMQC
alternative label: HMQC NMR
definition: A type of heteronuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between protons and the nuclei to which they are covalently bound. [CHMO]

diffusion-ordered spectroscopy
type: Class
subclass of: nuclear magnetic resonance diffusometry
alternative label: DOSY
alternative label: DOSY NMR
alternative label: diffusion NMR
alternative label: diffusion ordered NMR spectroscopy
alternative label: diffusion ordered spectroscopy
alternative label: diffusion-edited NMR spectroscopy
alternative label: diffusion-edited spectroscopy
alternative label: diffusion-ordered NMR spectroscopy
alternative label: diffusion-ordered nuclear magnetic resonance spectroscopy
definition: A type of NMR spectroscopy using pulsed-field gradients where the rate of decay of NMR signals in each component of a sample mixture is measured across a series of experiments. The rate of signal decay is proportional to the diffusion coefficient for each component. [CHMO]

nuclear magnetic resonance composite pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
definition: A set of finely tuned RF pulses that achieve the same result with greater precision and fewer imperfections as a result of field inhomogeneity and off-resonance effects than a single RF pulse. [Allotrope]

HNCOCA
type: Class
subclass of: triple-resonance spectroscopy
alternative label: HN(CO)CA
alternative label: HN(CO)CA experiment
alternative label: HNCOCA experiment
definition: A triple-resonance NMR experiment used to determine the chemical shifts of nuclei in a (isotopically enriched) protein. The chemical shift of the (backbone) amide proton is correlated with the chemical shift of the covalently bound nitrogen and the alpha-carbon of the preceding residue. [CHMO]

nuclear Overhauser effect difference spectroscopy
type: Class
subclass of: one-dimensional nuclear Overhauser enhancement spectroscopy
alternative label: 1D NOE Difference
alternative label: 1D NOE difference spectroscopy
alternative label: NOE DIFF
alternative label: NOE Difference
alternative label: NOE-DIFF
alternative label: NOE-Difference
alternative label: NOE-difference
alternative label: NOEd
definition: A 1D NMR experiment in which a 1D spectrum is subtracted from a spectrum acquired under steady-state NOE conditions. [CHMO]

wideband alternating-phase low-power technique for zero residual splitting
type: Class
subclass of: composite pulse decoupling sequence
alternative label: WALTZ
alternative label: WALTZ pulse sequence
alternative label: WALTZ sequence
definition: A sequence of composite pulses designed to remove signal splitting due to heteronuclear J-couplings in multinuclear liquid NMR experiments. Also used to allow transfer of magnetization between nuclei (by making the spins precess with at the same chemical shift and thus enjoy strong coupling - isotropic mixing). J. Magn. Reson., (1983), 52, pg 335. [CHMO]

spin decoupling employing ultra-broadband-inversion sequences generated via simulated annealing
type: Class
subclass of: composite pulse decoupling sequence
alternative label: SUSAN
alternative label: SUSAN pulse sequence
alternative label: SUSAN sequence
definition: A sequence of composite pulses designed to remove signal splitting due to heteronuclear J-couplings in multinuclear liquid NMR experiments. For the pulse sequence see J. Magn. Reson. A, (1994), 106, pg 241. [CHMO]

zero-field optically detected magnetic resonance
type: Class
subclass of: AFP_0001211
alternative label: ZF-ODMR
alternative label: ZFODMR
alternative label: Zf-ODMR
alternative label: zero-field (zf) ODMR
alternative label: zero-field ODMR
alternative label: zf-ODMR
definition: A double resonance technique in which transitions between spin sublevels at zero applied magnetic field are detected by optical means (i.e. the polarization or the intensity of light emitted or absorbed by the sample depends on the population distribution in the spin levels). Usually these are sublevels of a triplet and the transitions are induced by microwaves. [CHMO]

quadrupolar Carr-Purcell-Meiboom-Gill pulse sequence
type: Class
subclass of: Carr-Purcell-Meiboom-Gill pulse sequence
alternative label: QCPMG
alternative label: QCPMG NMR
alternative label: QCPMG pulse sequence
alternative label: QCPMG sequence
alternative label: quadrupolar Carr, Purcell,Meiboom, Gill pulse sequence
alternative label: quadrupolar Carr-Purcell Meiboom-Gill pulse sequence
definition: A pulse sequence which is applied during nuclear magnetic resonance spectroscopy of quadrupolar nuclei, to measure spin-spin (T2) relaxation times. In the solid state, the sequence is used to achieve sensitivity enhancement for nuclei with low gyromagnetic ratios. For the pulse sequence see J. Phys. Chem. A, (1997), 101, pg 8597. [CHMO]

steady-state nuclear Overhauser enhancement spectroscopy
type: Class
subclass of: two-dimensional nuclear Overhauser enhancement spectroscopy
alternative label: steady state NOESY
alternative label: steady state nOesy
alternative label: steady-state NOESY
alternative label: steady-state nOesy
alternative label: steady-state nuclear Overhauser enhancement spectrometry
change note: 2024-09-11 Removed [Amgen] attribution as this is purely a [CHMO] term.
definition: A type of homonuclear NMR spectroscopy where a second frequency dimension is employed, based on the nuclear Overhauser enhancement effect in which correlations are seen between nuclei that are spatially proximate within a molecule (<= 6 Angstrom apart). In this technique, the saturation of a particular proton resonance (signal) perturbs the intensities of signals from spatially proximate nuclei. [CHMO]

solution-state nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: solution NMR
alternative label: solution-state NMR
definition: A type of spectroscopy where the response of nuclei with non-zero spin, in a sample dissolved in a deuterated solvent, to a perturbing magnetic field is detected. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them. [CHMO]

decoupling in the presence of scalar interactions
type: Class
subclass of: composite pulse decoupling sequence
alternative label: DIPSI
alternative label: DIPSI pulse sequence
alternative label: DIPSI sequence
definition: A sequence of composite pulses designed to remove signal splitting due to heteronuclear J-couplings in multinuclear liquid NMR experiments. Also used to allow transfer of magnetization between nuclei (by making the spins precess with at the same chemical shift and thus enjoy strong coupling - isotropic mixing). For the pulse sequence see J. Magn. Reson., (1988), 77, pg 274. [CHMO]

automatic phase correction
type: Class
subclass of: phase correction
definition: The application of a mathematical operation to both the real and imaginary parts of the complex numbers represented by the FID recorded as the sample magnetisation vector relaxes from its excited state vector back to its equilibrium bulk magnetisation population as adjusted by automated algorithms in the data acquisition or processing software. [Allotrope]

electron nuclear double resonance
type: Class
subclass of: AFP_0002129
alternative label: ENDOR
alternative label: ENDOR spectroscopy
alternative label: EPR detected NMR

triple quantum filter
type: Class
subclass of: multiple quantum filter
alternative label: TQF
definition: An NMR technique used to edit the NMR response from a sample by selecting only three-spin coupled systems, usually achieved by appropriate cycling of the phase (direction of application) of the pulses in an experiment and of the receiver. [CHMO]

continuous-wave electron nuclear double resonance spectroscopy
type: Class
subclass of: electron nuclear double resonance
alternative label: c.w. ENDOR
alternative label: continous wave ENDOR
alternative label: continuous wave electron nuclear double resonance spectroscopy
alternative label: cw ENDOR
alternative label: cw-ENDOR
definition: A type of spectroscopy where a sample is irradiated by a microwave frequency which matches an electron resonance transition, whilst nuclei in the vicinty of the unpaired eletron are excited by a radio frequency sweep. [CHMO]

two-dimensional heteronuclear single quantum coherence-total correlation spectroscopy
type: Class
subclass of: heteronuclear two-dimensional nuclear magnetic resonance spectroscopy
alternative label: 2D HSQC-TOCSY
alternative label: two-dimensional heteronuclear single quantum coherence spectroscopy
definition: A 2D NMR experiment that correlates chemical shifts of a heteronucleus and proton via 1J(X-H) heteronuclear coupling showing two different spectra cross-peaks, one for direct 1H-heteronuclear connectivity (HSQC cross-peak) and the second relayed 1H-heteronucleus connectivities due to cumulative transfer. [Allotrope]

jump and return pulse sequence
type: Class
subclass of: solvent suppression pulse sequence
alternative label: JR
alternative label: JR pulse sequence
alternative label: JR sequence
alternative label: jump and return
alternative label: jump-and-return
alternative label: jump-and-return pulse sequence
definition: A pulse cluster used for solvent suppression consisting of two RF pulses separated by a delay with conditions set such that the solvent signal alone is rendered unobservable by the second pulse. For the pulse sequence see J. Am. Chem. Soc., (1982), 104, pg 7310. [CHMO]

gradient-selected heteronuclear multiple quantum coherence
type: Class
subclass of: heteronuclear multiple quantum coherence
alternative label: gHMQC
alternative label: gradient HMQC
alternative label: gradient heteronuclear multiple quantum coherence
alternative label: gradient-selected HMQC
definition: A type of heteronuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between protons and the nuclei to which they are covalently bound. A spatially inhomogeneous magnetic field is applied with a defined gradient and used to either select a particular signal or to render unwanted signals undetectable. [CHMO]

off-resonance decoupling
type: Class
subclass of: nuclear magnetic resonance decoupling
definition: Selected nuclei of a specified isotope are unselectively irradiated with a soft RF pulse. The frequency range for the nuclei being irradiated typically differs from the frequency range for the nuclei relaxing back to their bulk magnetisation relaxation state. [Allotrope]

1H continuous-wave nuclear magnetic resonance spectroscopy
type: Class
subclass of: continuous-wave nuclear magnetic resonance spectroscopy
alternative label: 1H NMR absorption spectroscopy
alternative label: 1H c.w. NMR
alternative label: 1H continuous wave nuclear magnetic resonance spectroscopy
alternative label: 1H cw-NMR
definition: A type of spectroscopy where the energy states of 1H nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Spectra are obtained by scanning a range of radio frequencies. [CHMO]

HNCA
type: Class
subclass of: triple-resonance spectroscopy
alternative label: HNCA experiment
definition: A triple-resonance NMR experiment used in to determine the chemical shifts of nuclei in a (isotopically enriched) protein. The chemical shift of the (backbone) amide proton is correlated with the chemical shift of the covalently bound nitrogen and the alpha carbons of the same and preceding residues. [CHMO]

1H electron nuclear double resonance spectroscopy
type: Class
subclass of: pulsed electron nuclear double resonance spectroscopy
alternative label: 1H ENDOR
alternative label: 1H ENDOR spectroscopy
alternative label: hydrogen-1 ENDOR
alternative label: hydrogen-1 ENDOR spectroscopy
alternative label: proton ENDOR
alternative label: proton ENDOR spectroscopy
definition: A type of spectroscopy where a microwave frequency pulse is used to saturate the electron resonance transitions in the 1H nuclei of a sample, and a radio frequency pulse is used excite a nuclear transition. [CHMO]

central transition magic angle spinning
type: Class
subclass of: magic angle spinning
alternative label: CTMAS
alternative label: CTMAS NMR
alternative label: central-transition magic-angle spinning
definition: An NMR experiment where the selective excitation of central transitions during magic angle spinning is used for recording high-resolution NMR spectra of quadrupolar nuclei in solids. [CHMO]

modulus addition using spatially separated echo spectroscopy
type: Class
subclass of: pulsed field-gradient spin echo nuclear magnetic resonance spectroscopy
alternative label: MASSEY
alternative label: MASSEY NMR
definition: An NMR experiment used to measure self-diffusion coefficients via signal attenuation which occurs due to diffusion during the application of pulsed field gradients. This experiment also corrects for the effects of imperfect pulsed field gradients. [CHMO]

proton-decoupled nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: proton-decoupled NMR
alternative label: proton-decoupled NMR spectroscopy
definition: A type of NMR spectroscopy where (J/scalar) couplings to 1H nuclei are cancelled by applying radio frequency radiation to saturate or otherwise manipulate the 1H spins such that no evolution of the coupling occurs. [CHMO]

heteronuclear three-dimensional nuclear magnetic resonance spectroscopy
type: Class
subclass of: three-dimensional nuclear magnetic resonance spectroscopy
alternative label: heteronuclear 3D NMR
definition: Any type of nuclear magnetic resonance spectroscopy in which three independent frequency dimensions are employed for the correlation and dispersal of signals. Each signal is described by three frequencies, arising from a combination of protons and heteronuclei, thus effecting the distribution of signals within a cube. [CHMO]

single quantum filter
type: Class
subclass of: multiple quantum filter
alternative label: SQF
definition: An NMR technique used to edit the NMR response from a sample by selecting only uncoupled spins (singlets), usually achieved by appropriate cycling of the phase (direction of application) of the pulses in an experiment and of the receiver. [CHMO]

heteronuclear multiple bond coherence
type: Class
subclass of: heteronuclear two-dimensional nuclear magnetic resonance spectroscopy
alternative label: HMBC
alternative label: HMBC NMR
definition: A type of heteronuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between protons and nuclei which are 2-3 bonds removed. [CHMO]

nuclear magnetic resonance pulse sequence
type: Class
subclass of: AFP_0002536
alternative label: NMR pulse sequence
alternative label: pulse sequence
definition: A series of short (microsecond) bursts (pulses) of RF radiation separated by delays (of defined duration) designed to interact with, and manipulate the magnetic moments of spin-active nuclei during NMR spectroscopy. [CHMO]

post-acquisition water suppression
type: Class
subclass of: nuclear magnetic resonance spectroscopy data processing
change note: 2024-09-11 Replaced definition with an Allotrope written one.
definition: Post-acquisition water suppression is a data processing used to suppress the signal from the water solvent after data acquisition. [Allotrope]

combined rotation and multiple pulse spectroscopy
type: Class
subclass of: magic angle spinning
alternative label: CRAMPS
alternative label: combined rotation and multiple pulse spectrometry
definition: A type of NMR spectroscopy using a solid sample. Anisotropic interactions between nuclei, which are usually averaged by Brownian motion in liquid samples, cause significant line broadening in solid state NMR, but can be averaged to zero by spinning the sample very rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field).The combination of multiple-pulse NMR experiments and magic angle spinning. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them. [CHMO]

variable angle correlation spectroscopy
type: Class
subclass of: polarization inversion and spin exchange at the magic angle
alternative label: 2D VACSY
alternative label: 2D VACSY NMR
alternative label: VACSY
alternative label: VACSY NMR
alternative label: variable-angle correlation spectroscopy
definition: A two-dimensional solid-state NMR experiment which correlates the chemical shift anisotropy of a nucleus with its isotropic chemical shift by performing a series of experiments each at a different spinning angle relative to the magnetic field. [CHMO]

rotating frame Overhauser effect spectroscopy
type: Class
subclass of: two-dimensional nuclear Overhauser enhancement spectroscopy
alternative label: CAMELPSIN
alternative label: ROESY
alternative label: ROESY NMR
alternative label: cross-relaxation appropriate for minimolecules emulated by locked spins
alternative label: rOesy
alternative label: rotating frame Overhauser effect spectrometry
alternative label: rotating frame Overhauser enhancement spectrometry
alternative label: rotating frame Overhauser enhancement spectroscopy
alternative label: rotational Overhauser effect spectroscopy
definition: A type of heteronuclear NMR spectroscopy where a second frequency dimension is employed, based on the nuclear Overhauser enhancement (NOE) effect in which correlations are seen between nuclei that are spatially proximate within a molecule (<= 6 Angstrom apart). Spin-locking is employed to ensure that correlation between spins, which are close in space but have zero NOE, are seen. This technique is used for molecules whose tumbling regime lies at the border of positive and negative NOE responses. [CHMO]

homonuclear decoupling
type: Class
subclass of: nuclear magnetic resonance decoupling
definition: The nuclei being irradiated with an RF pulse is the same nuclei and isotope as the nuclei being observed to relax back to equilibrium for generation of the NMR spectrum. [Allotrope]

two-dimensional J-spectroscopy-diffusion-ordered spectroscopy
type: Class
subclass of: three-dimensional diffusion-ordered spectroscopy
alternative label: 2DJ-DOSY
alternative label: 3D 2DJ-DOSY
alternative label: 3D DOSY-2DJ
alternative label: DOSY-2DJ
alternative label: diffusion-ordered spectroscopy-two-dimensional J-spectroscopy
definition: A type of three-dimensional NMR experiment in which the signals of a 2D J-spectrum are dispersed along a third frequency axis according to diffusion coefficient. [CHMO]

flip flop spectroscopy
type: Class
subclass of: nuclear magnetic resonance pulse sequence
alternative label: FLOPSY
alternative label: flip-flop spectroscopy
definition: A sequence of composite pulses designed to allow isotropic mixing of magnetisation between nuclei. For the pulse sequence see J. Magn.Reson., (1988), 77, pg 274. [CHMO]

hard pulse
type: Class
subclass of: AFP_0001084
definition: An RF pulse that unselectively excites a spin system over a given bandwidth. [Allotrope]

statistical total correlation spectroscopy
type: Class
subclass of: total correlation spectroscopy
alternative label: STOCSY
alternative label: STOCSY NMR
alternative label: statistical COSY
definition: A type of homonuclear NMR spectroscopy which reveal correlations between all nuclei of a spin-system. This technique exploits the correlations seen between the intensities of spectral features of multiple spectra so as to obtain a statistically derived spectrum. This technique is of particular value for metabolic profiling. [CHMO]

magic angle spinning
type: Class
subclass of: solid-state nuclear magnetic resonance spectroscopy
alternative label: MAS NMR
alternative label: MAS NMR spectroscopy
alternative label: MAS-NMR
alternative label: SS-MAS NMR
alternative label: magic angle spinning nuclear magnetic resonance spectrometry
alternative label: magic-angle spinning
alternative label: solid-state magic-angle-spinning NMR
alternative label: ss-MAS-NMR
definition: A type of NMR spectroscopy using a solid sample. Anisotropic interactions between nuclei, which are usually averaged by Brownian motion in liquid samples, cause significant line broadening in solid state NMR, but can be averaged to zero by spinning the sample very rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field). [CHMO]

pulsed nuclear magnetic resonance spectroscopy
type: Class
subclass of: AFP_0000326
alternative label: NMR
alternative label: NMR spectrometry
alternative label: NMR spectroscopy
alternative label: nuclear magnetic resonance spectrometry
alternative label: nuclear magnetic resonance spectroscopy
alternative label: pulsed nuclear magnetic resonance spectrometry
definition: A type of spectroscopy where the energy states of spin-active nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them. [CHMO]

magic sandwich high-order truncation pulse sequence
type: Class
subclass of: magic angle spinning decoupling pulse sequence
alternative label: MSHOT3
alternative label: MSHOT3 pulse sequence
alternative label: MSHOT3 sequence
alternative label: magic sandwich high order truncation
alternative label: magic sandwich high-order truncation
definition: A sequence of pulses used in magic angle spinning NMR to remove the effect of homonuclear dipolar couplings. For the pulse sequence see J. Chem. Phys., (1997), 125, pg 291. [CHMO]

gradient-selected correlation spectroscopy
type: Class
subclass of: correlation spectroscopy
alternative label: gCOSY
alternative label: gradient-selected COSY
definition: A type of homonuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between nuclei that are J-coupled (usually <= 3 bonds apart). A spatially inhomogeneous magnetic field is applied with a defined gradient and used to either select a particular signal or to render unwanted signals undetectable. [CHMO]

two-dimensional total correlation spectroscopy
type: Class
subclass of: total correlation spectroscopy
alternative label: 2D TOCSY
alternative label: 2D-TOCSY
alternative label: two-dimensional TOCSY
definition: A type of homonuclear NMR spectroscopy where a second frequency dimension is employed to disperse the signals and which reveal correlations between all nuclei of a spin-system. [CHMO]

phase cycle
type: Class
subclass of: AFP_0000759
alternative label: phase sequence
definition: A technique used in FT NMR experiments whereby the sense of application (or phase) of the RF pulses is altered on repeating the experiment such that addition of the resulting signals results in increased intensity for the signals of interest, elimination of artefacts and more effective noise reduction. [CHMO]

FID zero filling
type: Class
subclass of: nuclear magnetic resonance spectroscopy data processing
alternative label: z-filling
definition: A recorded RF signal in NMR spectroscopy observed as the perturbed sample magnetisation relaxes back to its bulk magnetisation population state that has been suffixed with a set of data points containing many zeros. [Allotrope]

two-dimensional nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: 2-D NMR
alternative label: 2D NMR
alternative label: 2D NMR spectrometry
alternative label: 2D NMR spectroscopy
alternative label: 2D nuclear magnetic resonance
alternative label: 2D nuclear magnetic resonance spectrometry
alternative label: two-dimensional NMR
alternative label: two-dimensional nuclear magnetic resonance spectrometry
definition: An NMR experiment in which a second frequency dimension is employed to disperse the signals and reveal correlations between interacting nuclei. [CHMO]

HN(CO)CAHA
type: Class
subclass of: triple-resonance spectroscopy
alternative label: HN(CO)CAHA experiment
definition: A triple-resonance NMR experiment used to determine the chemical shifts of nuclei in a (isotopically enriched) protein. The chemical shift of the (backbone) amide proton is correlated with the chemical shift of the covalently bound nitrogen and with the alpha-carbon and proton of the preceding residue. The experiment name describes the path taken by the magnetization during the experiment. [CHMO]

homospoil pulse sequence
type: Class
subclass of: nuclear magnetic resonance pulse sequence
change note: 2024-09-11 Changed [Amgen] attribution to [Allotrope].
definition: Homospoil is an NMR pulse sequence that results in linear variation of the magnetic field in the z direction. After the homospoil pulse, transverse magnetization in the slices of sample will acquire additional phase, which will vary with height. Net x-y plane magnetization will be zero. [Allotrope]

ZZ-filter
type: Class
subclass of: AFP_0000759
alternative label: ZZ filter
definition: A technique used in NMR experiments to remove unwanted signals from the spectrum by destroying the magnetization giving rise to these signals using a pulsed filed gradient whilst the magnetization of interest is maintained in a state which is unaffected by the pulsed field gradient (ZZ-state). [CHMO]

17O electron nuclear double resonance spectroscopy
type: Class
subclass of: pulsed electron nuclear double resonance spectroscopy
alternative label: 17O ENDOR
alternative label: 17O ENDOR spectroscopy
alternative label: oxygen-17 ENDOR
alternative label: oxygen-17 ENDOR spectroscopy
definition: A type of spectroscopy where a microwave frequency pulse is used to saturate the electron resonance transitions in the 17O nuclei of a sample, and a radio frequency pulse is used excite a nuclear transition. [CHMO]

phase alternated rotation of magnetization
type: Class
subclass of: composite pulse decoupling sequence
alternative label: PAR
alternative label: PAR pulse sequence
alternative label: PAR sequence
alternative label: phase-alternated rotation of magnetization
definition: A sequence of composite pulses designed to remove signal splitting due to heteronuclear J-couplings in multinuclear liquid NMR experiments. [CHMO]

zero order phase correction
type: Class
subclass of: phase correction
definition: The application of a phase correction algorithm to a Fourier transform NMR spectra such that it is optimised to give maximum values for the frequency dependent real part of the frequency signal (and minimum values for the imaginary part) of the FID Fourier transform complex number set. [Allotrope]

Waugh, Huber, Haeberlin pulse sequence
type: Class
subclass of: magic angle spinning decoupling pulse sequence
alternative label: WAHUHA
alternative label: WAHUHA pulse sequence
alternative label: WAHUHA sequence
alternative label: Waugh Huber Haeberlin sequence
alternative label: Waugh-Huber-Haeberlin pulse sequence
alternative label: Waugh-Huber-Haeberlin sequence
definition: A pulse sequence used in magic angle spinning NMR to remove the effects of homonuclear dipolar coupling. For the pulse sequence see Phys. Rev. Lett., (1968), 20, pg 180. [CHMO]

high-resolution diffusion-ordered spectroscopy
type: Class
subclass of: diffusion-ordered spectroscopy
alternative label: HR-DOSY
alternative label: high resolution DOSY
alternative label: high resolution diffusion-ordered spectroscopy
alternative label: high-resolution DOSY
definition: A type of NMR spectroscopy using pulsed-field gradients where the rate of decay of NMR signals in each component of a sample mixture is measured across a series of experiments. The rate of signal decay is proportional to the diffusion coefficient for each component. The diffusion coefficient for each peak is measured and this information is used to construct a 2D spectrum. [CHMO]

heteronuclear multiple quantum coherence-diffusion-ordered spectroscopy
type: Class
subclass of: three-dimensional diffusion-ordered spectroscopy
alternative label: 3D DOSY-HMQC
alternative label: 3D HMQC-DOSY
alternative label: DOSY-HMQC
alternative label: HMQC-DOSY
alternative label: diffusion-ordered spectroscopy-heteronuclear multiple quantum coherence
definition: A type of three-dimensional NMR experiment in which the signals of a 2D HMQC spectrum are dispersed along a third frequency axis according to diffusion coefficient. [CHMO]

solid-state nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: SS-NMR
alternative label: SSNMR
alternative label: solid state NMR
alternative label: solid state nuclear magnetic resonance spectrometry
alternative label: solid-state NMR
definition: A type of spectroscopy where the response of nuclei with non-zero spin, in a solid sample, to a perturbing magnetic field is detected. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them. [CHMO]

one-dimensional total correlation spectroscopy
type: Class
subclass of: total correlation spectroscopy
alternative label: 1D TOCSY
alternative label: 1D-TOCSY
alternative label: one-dimensional TOCSY
definition: A type of homonuclear NMR spectroscopy which reveal correlations between all nuclei of a spin-system. An individual 1H resonance is selected and inverted to yield a spectrum of all hydrogens directly or indirectly scalar coupled to it. [CHMO]

states acquisition
type: Class
subclass of: AFP_0000759
definition: A technique used in multidimensional NMR experiments to achieve frequency discrimination of the signals in the additional dimensions. [CHMO]

insensitive nuclei enhancement by polarization transfer
type: Class
subclass of: AFP_0000759
alternative label: INEPT
alternative label: INEPT NMR
definition: A heteronuclear NMR experiment in which magnetization arising from 1H nuclei is transferred to covalently bound heteronuclei, thereby enhancing the NMR signal of the heteronuclei. [CHMO]

ultra-high-field nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: ultra high field NMR
alternative label: ultra high-field NMR
alternative label: ultrahigh-field NMR
definition: A type of spectroscopy where the energy states of spin-active nuclei placed in a static (>900 MHz) magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them. [CHMO]

broadband decoupling
type: Class
subclass of: nuclear magnetic resonance decoupling
definition: All nuclei of a specified isotope are unselectively irradiated with an RF pulse. [Allotrope]

three-dimensional nuclear Overhauser spectroscopy-heteronuclear single quantum coherence
type: Class
subclass of: heteronuclear three-dimensional nuclear magnetic resonance spectroscopy
alternative label: 3D NOESY-HSQC
definition: A 3D NMR experiment in which the chemical shifts of protons are correlated with the chemical shifts of spatially proximate protons (<6 Angstrom) and with the shifts of the heteronuclei bound to these proximate protons. [CHMO]

saturation transfer double difference nuclear magnetic resonance spectroscopy
type: Class
subclass of: saturation transfer difference nuclear magnetic resonance spectroscopy
alternative label: STDD-NMR
alternative label: saturation-transfer double-difference nuclear magnetic resonance spectroscopy
definition: A type of NMR spectroscopy where radio frequency pulses are used to induce an equal population of upper and lower spin states in ('saturate') certain selected protons, removing their signal from the NMR spectrum. The signal from two different samples is obtained simultaneously and common signals are cancelled automatically. Saturation-transfer double-difference NMR is used to detect the transient binding of small molecule ligands to macromolecular receptors. [CHMO]

X-filter
type: Class
subclass of: AFP_0000759
alternative label: heteronuclear nXQF element
definition: A technique used in NMR of isotopically enriched samples (usually 13C/15N) to select for, or to remove signals of protons bound to a particular isotope. [CHMO]

liquid-phase nuclear magnetic resonance spectroscopy
type: Class
subclass of: AFP_0000326
alternative label: liquid phase NMR
alternative label: liquid phase nuclear magnetic resonance spectroscopy
definition: A type of spectroscopy in the liquid phase where the energy states of spin-active nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. [CHMO]

three-dimensional diffusion-ordered spectroscopy
type: Class
subclass of: three-dimensional nuclear magnetic resonance spectroscopy
alternative label: 3D DOSY
alternative label: 3D DOSY NMR
alternative label: 3D-DOSY
definition: A type of three-dimensional NMR experiment in which the signals of a 2D NMR experiment are dispersed along a third frequency axis according to diffusion coefficient. [CHMO]

heteronuclear Overhauser enhancement spectroscopy
type: Class
subclass of: two-dimensional nuclear Overhauser enhancement spectroscopy
alternative label: HOESY
alternative label: HOESY NMR
alternative label: heteronuclear Overhauser effect spectrometry
alternative label: heteronuclear Overhauser effect spectroscopy
alternative label: heteronuclear Overhauser enhancement spectrometry
definition: A type of heteronuclear NMR spectroscopy where a second frequency dimension is employed, based on the nuclear Overhauser enhancement effect in which correlations are seen between nuclei that are spatially proximate within a molecule (<= 6 Angstrom apart). [CHMO]

one-dimensional nuclear magnetic resonance spectroscopy
type: Class
subclass of: pulsed nuclear magnetic resonance spectroscopy
alternative label: 1-D NMR
alternative label: 1D NMR
alternative label: 1D NMR spectrometry
alternative label: 1D NMR spectroscopy
alternative label: 1D nuclear magnetic resonance spectrometry
alternative label: 1D nuclear magnetic resonance spectroscopy
alternative label: one-dimensional nuclear magnetic resonance spectrometry
definition: A type of spectroscopy where the energy states of spin-active nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them, and the spectrum is obtained by plotting intensity vs. chemical shift or frequency. [CHMO]

saturation transfer difference nuclear magnetic resonance spectroscopy
type: Class
subclass of: nuclear Overhauser enhancement spectroscopy
alternative label: STD
alternative label: STD-NMR
alternative label: STD-NMR spectroscopy
alternative label: nuclear magnetic resonance saturation transfer difference (STD) spectroscopy
alternative label: nuclear magnetic resonance saturation transfer difference spectroscopy
alternative label: saturation transfer difference (STD) nuclear magnetic resonance spectroscopy
definition: A type of NMR spectroscopy where radio frequency pulses are used to induce an equal population of upper and lower spin states in ('saturate') certain selected protons, removing their signal from the NMR spectrum. The resulting spectrum is then subtracted from a reference spectrum obtained without saturation. Saturation-transfer NMR is used to detect the transient binding of small molecule ligands to macromolecular receptors. [CHMO]

heteronuclear correlation spectroscopy
type: Class
subclass of: heteronuclear two-dimensional nuclear magnetic resonance spectroscopy
alternative label: 2D heteronuclear correlation spectroscopy
alternative label: HETCOR
alternative label: HETCORR
alternative label: HETCOSY
alternative label: HETEROCOR
alternative label: hetCOSY
alternative label: heteronuclear COSY
alternative label: two-dimensional heteronuclear correlation spectroscopy
definition: A type of NMR spectroscopy where a second frequency dimension is employed to disperse the signals and reveal correlations between protons and heteronuclei. [CHMO]

phase correction
type: Class
subclass of: nuclear magnetic resonance spectroscopy data processing
definition: Application of a trigonometric mathematical operation to both the real and imaginary parts of the complex numbers represented by the FID recorded as the sample magnetization vector relaxes from its excited state vector back to its equilibrium bulk magnetization population. [Allotrope]

distortionless enhancement with polarization transfer retention of quaternaries
type: Class
subclass of: distortionless enhancement with polarization transfer
alternative label: DEPTQ
alternative label: DEPTQ NMR
change note: 2024-09-11 Changed [OSTHUS] attribution to [Allotrope].
definition: A type of spectroscopy where the energy states of 13C nuclei placed in a static magnetic field are interrogated by inducing transitions between the states via radio frequency irradiation. Each experiment consists of a sequence of radio frequency pulses with delay periods in between them.The 13C NMR signals are enhanced by transferring 1H magnetization to 13C nuclei and the phase of the signals reflects the multiplicity i.e. CH, CH2 or CH3). Separate methyl, methylene and methine spectra may be obtained. The quaternary carbon centres are also represented in the spectra, albeit with reduced intensities, and are rendered with similar 'signs' to methylene groups. [Allotrope]

nuclear Overhauser enhancement spectroscopy including chemical and conformational change
type: Class
subclass of: nuclear Overhauser enhancement spectroscopy
alternative label: EXSY
alternative label: exchange spectroscopy
alternative label: nuclear Overhauser enhancement spectrometry including chemical and conformational change
definition: A type of homonuclear NMR spectroscopy based on the nuclear Overhauser enhancement effect in which through space spin-lattice correlations are made between nuclei that are spatially proximate within a molecule (<= 6 Angstrom apart) but not directly bonded. The technique differs from the traditional NoE experiment in that it is also used to detect chemical and conformational change within the chemical moiety being examined. [Allotrope]

probe matching
type: Class
subclass of: AFP_0000485
subclass of: OBI_0000011
alternative label: matching
definition: Probe matching is a process of adjustment of an NMR probe that makes sure that only a minimal part of the power at the probe is wasted. [Allotrope]

locking
type: Class
subclass of: AFP_0003331
subclass of: OBI_0000011
definition: Locking is the process of establishing a magnetic field with a constant strength during an NMR measurement. [Allotrope]

shimming
type: Class
subclass of: AFP_0003485
subclass of: OBI_0000011
definition: Shimming is the process of adjusting the signal of an NMR spectrometer by changing the uniformity of the magnetic field. [Allotrope]

pulse program
type: Class
subclass of: AFR_0001501
definition: A pulse program is a programmatic plan that defines the pulse sequence that is applied to the excitation of a sample. [Allotrope]
example: pulse program of ssNMR

saturation recovery
type: Class
subclass of: AFP_0000759
definition: A saturation recovery experiment is used to measure T1, especially if the line has a very broad shape or if inversion is impossible. A pulse sequence is applied that keeps the magnetization in the x-y plane until saturation is reached and then magnetization recovers during T1. [Allotrope]

one-dimensional proton nuclear magnetic resonance spectrum
type: Class
subclass of: one-dimensional nuclear magnetic resonance spectrum
subclass of: proton nuclear magnetic resonance spectrum
alternative label: 1-D 1H NMR spectra
alternative label: 1-D 1H NMR spectrum
alternative label: 1D 1H NMR spectrum
alternative label: 1D NMR 1H spectra
definition: A plot of chemical shift vs. intensity for hydrogen-1 nuclei obtained by measuring the effect of the absorption of radio frequency radiation on nuclear spin-state transitions in the presence of a magnetic field. [CHMO]

cross-polarization magic angle spinning nuclear magnetic resonance spectrum
type: Class
subclass of: magic angle spinning nuclear magnetic resonance spectrum
alternative label: CP-MAS NMR spectra
alternative label: CP-MAS NMR spectrum
alternative label: CP/MAS NMR spectra
alternative label: CP/MAS NMR spectrum
alternative label: CPMAS NMR spectra
alternative label: CPMAS NMR spectrum
alternative label: cross-polarization magic angle spinning nuclear magnetic resonance spectra
definition: A nuclear magnetic resonance spectrum in which line broadening has been reduced to zero by spinning the sample very rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field) and cross polarisation has been used to enhance the signal from weakly coupled nuclei. [CHMO]

proton-decoupled nuclear magnetic resonance spectrum
type: Class
subclass of: AFR_0000263
change note: 2024-09-11 Changed [Amgen] attribution to [Allotrope].
definition: A proton-decoupled nuclear magnetic resonance spectrum is an NMR spectrum where coupling between protons and heteronuclei has been removed in order to improve the resolution of the spectrum of the heteronuclei. [Allotrope]

multiplicity code
type: Class
subclass of: AFC_0000050
definition: Code for describing the multiplicity of NMR peaks. [Allotrope]
example: singlet, doublet, multiplet

three-dimensional nuclear magnetic resonance spectrum
type: Class
subclass of: AFR_0000263
alternative label: 3D NMR spectra
alternative label: 3D NMR spectrum
alternative label: 3D-NMR spectra
alternative label: 3D-NMR spectrum
definition: A three-dimensional plot of chemical shift vs. intensity for spin-active nuclei obtained by measuring the effect of the absorption of radio frequency radiation on nuclear spin-state transitions in the presence of a magnetic field. Signals are defined in terms of three frequencies; by the chemical shift of a particular nucleus in one dimension and, in the other two, by the chemical shifts of correlated nuclei. [CHMO]

Carr-Purcell-Meiboom-Gill spectrum
type: Class
subclass of: AFR_0000263
alternative label: CPMG spectra
alternative label: CPMG spectrum
alternative label: CPMG spin-echo spectra
alternative label: CPMG spin-echo spectrum
definition: A plot of the nuclear magnetic resonance frequency vs. intensity composed of a series of peaks (separated by the reciprocal of a user-defined time delay in a CPMG pulse sequence) which describe the envelope of the full, static spectrum. [CHMO]

high-resolution magic angle spinning nuclear magnetic resonance spectrum
type: Class
subclass of: magic angle spinning nuclear magnetic resonance spectrum
alternative label: HR-MAS-NMR spectrum
alternative label: HRMAS spectra
alternative label: HRMAS spectrum
alternative label: HRMAS-NMR spectra
alternative label: high resolution MAS spectra
alternative label: high resolution MAS spectrum
alternative label: high-resolution MAS spectra
alternative label: high-resolution MAS spectrum
definition: A nuclear magnetic resonance spectrum in which line broadening has been averaged to zero by spinning the sample very rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field) and using a high-resolution magnetic susceptibility matching probe. [CHMO]

heteronuclear multiple bond coherence spectrum
type: Class
subclass of: two-dimensional nuclear magnetic resonance spectrum
alternative label: HMBC spectra
alternative label: HMBC spectrum
definition: A heteronuclear NMR spectrum where a second frequency dimension is employed to disperse the signals and reveal correlations between nuclei which are 2-3 bonds removed. [CHMO]

J-spectrum
type: Class
subclass of: two-dimensional nuclear magnetic resonance spectrum
alternative label: 2D J-resolved NMR spectra
alternative label: 2D J-resolved NMR spectrum
alternative label: J spectra
alternative label: J spectrum
alternative label: J-resolved NMR spectra
alternative label: J-resolved NMR spectrum
alternative label: J-resolved spectra
alternative label: J-resolved spectrum
alternative label: J-spectra
alternative label: NMR J-spectra
alternative label: NMR J-spectrum
definition: A two-dimensional NMR spectrum where signals are defined in terms of two frequencies; by the chemical shift of a particular nucleus in one dimension and, in the other, by the J-multiplets of correlated nuclei. [CHMO]

cross peak
type: Class
subclass of: nuclear magnetic resonance peak
change note: 2024-09-11 Changed [OSTHUS] attribution to [Allotrope].
definition: Peaks not found along the diagonal of a 2D NMR spectrum that give yield to information on spin-spin coupling or spatial proximity of the two nuclei being observed. [Allotrope]

nuclear Overhauser enhancement spectrum
type: Class
subclass of: AFR_0000263
alternative label: NOESY contour plot
alternative label: NOESY spectra
alternative label: NOESY spectrum
definition: A spectrum that shows the response of spin-active nuclei to radio frequency radiation in an applied magnetic field. The resonance frequencies of nuclei approximately 6 \AA apart which are correlated by the nuclear Overhauser enhancement effect are plotted with intensities proportional to the populations of nuclei. [CHMO]

diffusion-ordered spectrum
type: Class
subclass of: AFR_0000263
alternative label: DOSY spectrum
alternative label: diffusion-edited NMR spectra
alternative label: diffusion-edited NMR spectrum
alternative label: diffusion-edited spectra
alternative label: diffusion-edited spectrum
definition: A two- or three-dimensional plot of one- or two-dimensional NMR spectra vs. the diffusion coefficients of the species involved. [CHMO]

two-dimensional nuclear magnetic resonance spectrum
type: Class
subclass of: AFR_0000263
alternative label: 2D NMR spectra
alternative label: 2D NMR spectrum
alternative label: 2D-NMR spectra
alternative label: 2D-NMR spectrum
definition: A two-dimensional plot of chemical shift vs. intensity for spin-active nuclei obtained by measuring the effect of the absorption of radio frequency radiation on nuclear spin-state transitions in the presence of a magnetic field. Signals are defined in terms of two frequencies; by the chemical shift of a particular nucleus in one dimension and, in the other, by the chemical shift of a correlated nucleus. [CHMO]

one-dimensional nuclear magnetic resonance spectrum
type: Class
subclass of: AFR_0000263
alternative label: 1D NMR spectra
alternative label: 1D NMR spectrum
alternative label: 1D-NMR spectra
alternative label: 1D-NMR spectrum
definition: A plot of chemical shift vs. intensity for spin-active nuclei obtained by measuring the effect of the absorption of radio frequency radiation on nuclear spin-state transitions in the presence of a magnetic field. [CHMO]

heteronuclear correlation spectrum
type: Class
subclass of: AFR_0000263
alternative label: HETCOR spectrum
definition: A spectrum obtained from a heteronuclear correlation experiment. [CHMO]

correlation spectroscopy spectrum
type: Class
subclass of: two-dimensional nuclear magnetic resonance spectrum
alternative label: COSY NMR spectra
alternative label: COSY NMR spectrum
alternative label: COSY spectra
alternative label: COSY spectrum
definition: A two-dimensional spectrum in which the position of a peak, in one dimension, corresponds to the chemical shift of a particular nucleus and, in the other dimension, to the chemical shift of a nucleus which is J-coupled to the first. [CHMO]

nuclear magnetic resonance spectrum peak assignment target
type: Class
subclass of: AFR_0000024
alternative label: NMR spectrum peak assignment target
definition: The description of the specific part a chemical moeity that is assigned to a NMR peak. [Allotrope]
example: nucleus

distortionless enhancement with polarization transfer spectrum
type: Class
subclass of: AFR_0000263
alternative label: DEPT NMR spectrum
alternative label: DEPT spectrum
definition: A nuclear magnetic resonance spectrum where the where the nuclei of interest are carbon-13 nuclei, the signals from which are enhanced by the transfer of magnetisation from 1H nuclei. [CHMO]

magic-angle spinning quadrupolar Carr-Purcell-Meiboom-Gill spectrum
type: Class
subclass of: solid-state quadrupolar Carr-Purcell-Meiboom-Gill spectrum
alternative label: MAS QCPMG spectra
alternative label: MAS QCPMG spectum
alternative label: MAS-QCPMG spectra
alternative label: MAS-QCPMG spectrum
alternative label: QCPMG MAS spectra
alternative label: QCPMG MAS spectrum
alternative label: QCPMG-MAS spectra
alternative label: QCPMG-MAS spectrum
definition: A plot of the nuclear magnetic resonance frequency vs. intensity composed of a series of peaks (separated by the reciprocal of a user-defined time delay in a QCPMG pulse sequence) which describe the envelope of the full, static spectrum. Line broadening has been averaged to zero by spinning the solid sample very rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field). [CHMO]

solid-state quadrupolar Carr-Purcell-Meiboom-Gill spectrum
type: Class
subclass of: solid-state nuclear magnetic resonance spectrum
alternative label: QCPMG spectra
alternative label: QCPMG spectrum
alternative label: solid-state QCPMG spectra
alternative label: solid-state QCPMG spectum
definition: A plot of the nuclear magnetic resonance frequency vs. intensity composed of a series of peaks (separated by the reciprocal of a user-defined time delay in a QCPMG pulse sequence) which describe the envelope of the full, static spectrum. [CHMO]

solid-state nuclear magnetic resonance spectrum
type: Class
subclass of: AFR_0000263
alternative label: solid-state NMR spectra
alternative label: solid-state nuclear magnetic resonance spectra
definition: A plot of the resonance frequency of nuclei in the same magnetic environment on a scale relative to their resonance frequency and with intensities proportional to the populations of nuclei in those environments for solid samples. [CHMO]

continuous-wave nuclear magnetic resonance spectrum
type: Class
subclass of: AFR_0000068
alternative label: NMR absorption spectra
alternative label: NMR absorption spectrum
alternative label: c.w. NMR spectra
alternative label: c.w. NMR spectrum
alternative label: continuous wave nuclear magnetic resonance spectra
alternative label: continuous wave nuclear magnetic resonance spectrum
alternative label: continuous-wave nuclear magnetic resonance spectra
alternative label: cw-NMR spectra
alternative label: cw-NMR spectrum
definition: A plot of the absorption of radio frequency radiation vs. frequency for spin-active nuclei. [CHMO]

two-dimensional nuclear Overhauser enhancement spectrum
type: Class
subclass of: nuclear Overhauser enhancement spectrum
subclass of: two-dimensional nuclear magnetic resonance spectrum
alternative label: 2D NOESY spectra
alternative label: 2D NOESY spectrum
alternative label: 2D NOESY-NMR spectra
alternative label: 2D NOESY-NMR spectrum
definition: A two-dimensional spectrum which plots the resonance frequency of homonuclear nuclei approximately 6 \AA apart which are correlated by the nuclear Overhauser enhancement effect. The resonance frequencies are plotted with intensities proportional to the populations of nuclei. [CHMO]

1H continuous-wave nuclear magnetic resonance spectrum
type: Class
subclass of: continuous-wave nuclear magnetic resonance spectrum
alternative label: 1H NMR absorption spectra
alternative label: 1H NMR absorption spectrum
alternative label: 1H c.w. NMR spectra
alternative label: 1H c.w. NMR spectrum
alternative label: 1H cw-NMR spectra
alternative label: 1H cw-NMR spectrum
definition: A plot of the absorption of radio frequency radiation vs. frequency for hydrogen-1 nuclei. [CHMO]

proton nuclear magnetic resonance spectrum
type: Class
subclass of: AFR_0000263
alternative label: 1H NMR spectra
alternative label: 1H NMR spectrum
alternative label: 1H spectrum
alternative label: proton NMR spectra
alternative label: proton NMR spectrum
definition: Measurement of the effect of the absorption of radio frequency on nuclear spin-state transitions of hydrogen-1 in the presence of a magnetic field. [CHMO]

diagonal peak
type: Class
subclass of: nuclear magnetic resonance peak
definition: Peaks found along the diagonal of a 2D NMR spectrum. [Allotrope]

nuclear magnetic resonance peak
type: Class
subclass of: AFR_0000413
alternative label: NMR peak
definition: Peak resulting from a NMR acquisition. [Allotrope]

free induction decay
type: Class
subclass of: AFR_0000068
alternative label: FID
definition: A recorded RF signal in NMR spectroscopy observed as the perturbed sample magnetisation relaxes back to its bulk magnetisation population state. [Allotrope]

first derivative nuclear magnetic resonance spectrum
type: Class
subclass of: continuous-wave nuclear magnetic resonance spectrum
alternative label: first derivative NMR spectra
alternative label: first derivative NMR spectrum
definition: A plot of the change in intensity of absorption vs. the change in frequency as a function of the frequency of radiation applied, for spin-active nuclei. [CHMO]

magic angle spinning nuclear magnetic resonance spectrum
type: Class
subclass of: solid-state nuclear magnetic resonance spectrum
alternative label: MAS NMR spectrum
alternative label: MAS spectrum
definition: A nuclear magnetic resonance spectrum in which line broadening has been averaged to zero by spinning the solid sample very rapidly at the magic angle (54.74 deg. with respect to the direction of the magnetic field). [CHMO]

one-dimensional 19F nuclear magnetic resonance spectrum
type: Class
subclass of: one-dimensional nuclear magnetic resonance spectrum
definition: Fluorine-19 nuclear magnetic resonance is an analytical technique used to identify fluorine-containing compounds. 19F is one of the most important nuclei for NMR spectroscopy. [Wikipedia]

one-dimensional carbon 13 nuclear magnetic resonance spectrum
type: Class
subclass of: one-dimensional nuclear magnetic resonance spectrum
definition: Carbon-13 nuclear magnetic resonance most commonly known as carbon-13 NMR or 13C NMR or sometimes simply referred to as carbon NMR is the application of nuclear magnetic resonance (NMR) spectroscopy to carbon. It is analogous to proton NMR (1H NMR) and allows the identification of carbon atoms in an organic molecule just as proton NMR identifies hydrogen atoms. As such 13C NMR is an important tool in chemical structure elucidation in organic chemistry. 13C NMR detects only the 13C isotope of carbon, whose natural abundance is only 1.1%, because the main carbon isotope, 12C, is not detectable by NMR since it has zero net spin. [Wikipedia]

broad
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: br
alternative label: broad signal
definition: A NMR peak observed that is broad, usually indicating long range coupling or of exchangeable nature. [Allotrope]

quintet
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: qn
definition: A NMR peak observed as a quintet in an NMR spectrum assignable to a set of magnetically equivalent nuclei in first-order systems having two relative peak area of 1 : 4 : 6 : 4 : 1. [Allotrope]

doublet of doublets
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: dd
definition: A common NMR peak descriptor used to represent multiplicity of the peak observed as a doublet of doublets. [Allotrope]

singlet
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: s
definition: A single discrete isolated peak assignable to a set of magnetically equivalent nuclei of a chemical moiety. [Allotrope]

methylene envelope
type: NamedIndividual
type: multiplicity code
definition: A set of non discernable non-attributable overlapping methylene NMR peaks. [Allotrope]

doublet of triplets
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: dt
definition: A common NMR peak descriptor used to represent multiplicity of the peak observed as a doublet of triplets. [Allotrope]

doublet of doublet of doublets
type: NamedIndividual
type: multiplicity code
alternative label: ddd
definition: A common NMR peak descriptor used to represent multiplicity of the peak observed as a doublet of doublet of doublets. [Allotrope]

septet
type: NamedIndividual
type: multiplicity code
alternative label: sept
definition: A NMR peak observed as a septet in an NMR spectrum assignable to a set of magnetically equivalent nuclei in first-order systems having two relative peak area of 1 : 6 : 15 : 20 : 15 : 6 : 1. [Allotrope]

doublet of doublet of triplets
type: NamedIndividual
type: multiplicity code
alternative label: ddt
definition: A common NMR peak descriptor used to represent multiplicity of the peak observed as a doublet of doublet of triplets. [Allotrope]

sextet
type: NamedIndividual
type: multiplicity code
alternative label: sex
definition: A NMR peak observed as a sextet in an NMR spectrum assignable to a set of magnetically equivalent nuclei in first-order systems having two relative peak area of 1 : 5 : 10 : 10 : 5 : 1. [Allotrope]

multiplet
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: m
alternative label: mult
definition: A non discernable peak or set of overlapping peaks observed in an NMR spectra. [Allotrope]

octet
type: NamedIndividual
type: multiplicity code
alternative label: oct
definition: A NMR peak observed as a octet in an NMR spectrum assignable to a set of magnetically equivalent nuclei in first-order systems having two relative peak area of 1 : 7 : 21 : 35 : 35 : 21 : 7 : 1. [Allotrope]

triplet of triplets
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: tt
definition: A common NMR peak descriptor used to represent multiplicity of the peak observed as a triplet of triplets. [Allotrope]

doublet
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: d
definition: A NMR peak observed as a doublet in an NMR spectrum assignable to a set of magnetically equivalent nuclei in first-order systems having two relative peak area of 1 : 1. [Allotrope]

quartet
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: q
definition: An NMR peak observed as a quartet in an NMR spectrum assignable to a set of magnetically equivalent nuclei in first-order systems having two relative peak area of 1 : 3 : 3 : 1. [Allotrope]

triplet
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: t
definition: A NMR peak observed as a triplet in an NMR spectrum assignable to a set of magnetically equivalent nuclei in first-order systems having two relative peak area of 1 : 2 : 1. [Allotrope]

doublet of doublet of doublet of doublets
type: NamedIndividual
type: multiplicity code
alternative label: dddd
definition: A common NMR peak descriptor used to represent multiplicity of the peak observed as a doublet of doublet of doublet of doublets. [Allotrope]

nonet
type: NamedIndividual
type: multiplicity code
alternative label: non
definition: A NMR peak observed as a nonet in an NMR spectrum assignable to a set of magnetically equivalent nuclei in first-order systems having two relative peak area of 1 : 8 : 28 : 56 : 70 : 56 : 28 : 8 : 1. [Allotrope]

triplet of doublets
type: NamedIndividual
type: multiplicity code
source: NMR Guidelines for ACS Journals, ACS Publications, 2013
alternative label: td
definition: A common NMR peak descriptor used to represent multiplicity of the peak observed as a triplet of doublets. [Allotrope]

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