Karplus equation
E467018
conformational analysis method
empirical equation
relationship in nuclear magnetic resonance spectroscopy
The Karplus equation is an empirical relationship in nuclear magnetic resonance (NMR) spectroscopy that correlates three-bond scalar coupling constants with dihedral angles, enabling the determination of molecular conformations.
All labels observed (1)
| Label | Occurrences |
|---|---|
| Karplus equation canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T4763372 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Karplus equation Context triple: [Martin Karplus, knownFor, Karplus equation]
-
A.
Bhabha–Corben equations
The Bhabha–Corben equations are relativistic wave equations in quantum electrodynamics that describe the dynamics of spinning charged particles, developed by physicists Homi J. Bhabha and H. C. Corben.
-
B.
Sabine reverberation formula
The Sabine reverberation formula is a foundational equation in architectural acoustics that relates a room’s reverberation time to its volume and total sound-absorbing surface.
-
C.
Herzberg–Teller approximation
The Herzberg–Teller approximation is a refinement in molecular spectroscopy that accounts for vibronic coupling by allowing electronic transition dipole moments to depend on nuclear coordinates, explaining intensity in otherwise forbidden transitions.
-
D.
Darwin–Fowler method
The Darwin–Fowler method is a statistical mechanics technique that uses complex analysis and generating functions to derive distribution laws for systems of many particles.
-
E.
Longuet-Higgins
Longuet-Higgins is the surname of a notable British family that includes influential figures in theoretical chemistry, cognitive science, and mathematics.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Karplus equation Target entity description: The Karplus equation is an empirical relationship in nuclear magnetic resonance (NMR) spectroscopy that correlates three-bond scalar coupling constants with dihedral angles, enabling the determination of molecular conformations.
-
A.
Bhabha–Corben equations
The Bhabha–Corben equations are relativistic wave equations in quantum electrodynamics that describe the dynamics of spinning charged particles, developed by physicists Homi J. Bhabha and H. C. Corben.
-
B.
Sabine reverberation formula
The Sabine reverberation formula is a foundational equation in architectural acoustics that relates a room’s reverberation time to its volume and total sound-absorbing surface.
-
C.
Herzberg–Teller approximation
The Herzberg–Teller approximation is a refinement in molecular spectroscopy that accounts for vibronic coupling by allowing electronic transition dipole moments to depend on nuclear coordinates, explaining intensity in otherwise forbidden transitions.
-
D.
Darwin–Fowler method
The Darwin–Fowler method is a statistical mechanics technique that uses complex analysis and generating functions to derive distribution laws for systems of many particles.
-
E.
Longuet-Higgins
Longuet-Higgins is the surname of a notable British family that includes influential figures in theoretical chemistry, cognitive science, and mathematics.
- F. None of above. chosen
Statements (49)
| Predicate | Object |
|---|---|
| instanceOf |
conformational analysis method
ⓘ
empirical equation ⓘ relationship in nuclear magnetic resonance spectroscopy ⓘ |
| appliesTo |
3J scalar coupling constants
ⓘ
three-bond heteronuclear coupling constants ⓘ vicinal proton–proton coupling constants ⓘ |
| assumes |
fixed average geometry for a given coupling pathway
ⓘ
smooth periodic dependence of coupling on dihedral angle ⓘ |
| basedOn | empirical fit to experimental NMR data ⓘ |
| correlates |
dihedral angles
ⓘ
three-bond scalar coupling constants ⓘ |
| developedBy | Martin Karplus ⓘ |
| field |
nuclear magnetic resonance spectroscopy
ⓘ
organic chemistry ⓘ physical chemistry ⓘ structural biology ⓘ |
| hasExtension |
generalized Karplus equations
ⓘ
stereospecific Karplus relationships ⓘ
linked to:
Karplus equation for NMR coupling constants
|
| hasGeneralForm | 3J = A cos²(θ) + B cos(θ) + C ⓘ |
| hasLimitation |
accuracy decreases for highly flexible systems
ⓘ
parameters are system-dependent ⓘ sensitive to averaging over multiple conformations ⓘ |
| hasMaximumCouplingNear |
0 degrees dihedral angle
ⓘ
180 degrees dihedral angle ⓘ |
| hasMinimumCouplingNear | 90 degrees dihedral angle ⓘ |
| hasParameter |
A
ⓘ
B ⓘ C ⓘ |
| hasPeriodicity | 360 degrees in dihedral angle ⓘ |
| hasVariable |
3J coupling constant
ⓘ
dihedral angle θ ⓘ |
| inspired | Karplus-type relationships for other couplings ⓘ |
| namedAfter | Martin Karplus ⓘ |
| parameterDependsOn |
bond geometry
ⓘ
substituents and electronic environment ⓘ type of nuclei involved ⓘ |
| publicationDecade | 1950s ⓘ |
| relatedTo |
J-coupling
ⓘ
NMR structure determination ⓘ conformational analysis ⓘ dihedral angle ⓘ |
| usedFor |
conformational analysis of organic molecules
ⓘ
conformational analysis of peptides and proteins ⓘ determination of molecular conformations ⓘ estimation of dihedral angles from NMR data ⓘ |
| usedIn |
carbohydrate conformational analysis
ⓘ
protein structure determination ⓘ small-molecule structure elucidation ⓘ solution-state NMR spectroscopy ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Karplus equation Description of subject: The Karplus equation is an empirical relationship in nuclear magnetic resonance (NMR) spectroscopy that correlates three-bond scalar coupling constants with dihedral angles, enabling the determination of molecular conformations.
Referenced by (1)
Full triples — surface form annotated when it differs from this entity's canonical label.