Herzberg–Teller approximation
E27647
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.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Herzberg–Teller approximation canonical | 2 |
| Herzberg–Teller expansion of transition moment | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T210286 — 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: Herzberg–Teller approximation Context triple: [Franck–Condon principle, relatedTo, Herzberg–Teller approximation]
-
A.
Born–Oppenheimer approximation
The Born–Oppenheimer approximation is a fundamental method in molecular quantum mechanics that simplifies calculations by treating nuclear motion as much slower than electronic motion, allowing their behaviors to be separated.
-
B.
Rayleigh–Schrödinger perturbation theory
Rayleigh–Schrödinger perturbation theory is a fundamental method in quantum mechanics for approximating the energies and states of a system by treating interactions as small corrections to an exactly solvable problem.
-
C.
Huang–Rhys factor
The Huang–Rhys factor is a dimensionless parameter in solid-state and molecular spectroscopy that quantifies the strength of electron–phonon (vibronic) coupling during electronic transitions.
-
D.
The Nature of the Chemical Bond
The Nature of the Chemical Bond is a landmark chemistry book by Linus Pauling that systematically explains chemical bonding using quantum mechanics and became one of the most influential scientific texts of the 20th century.
-
E.
Feynman–Hellmann theorem
The Feynman–Hellmann theorem is a result in quantum mechanics that relates the derivative of an energy eigenvalue with respect to a parameter in the Hamiltonian to the expectation value of the corresponding derivative of the Hamiltonian.
- 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: Herzberg–Teller approximation Target entity description: 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.
-
A.
Born–Oppenheimer approximation
The Born–Oppenheimer approximation is a fundamental method in molecular quantum mechanics that simplifies calculations by treating nuclear motion as much slower than electronic motion, allowing their behaviors to be separated.
-
B.
Rayleigh–Schrödinger perturbation theory
Rayleigh–Schrödinger perturbation theory is a fundamental method in quantum mechanics for approximating the energies and states of a system by treating interactions as small corrections to an exactly solvable problem.
-
C.
Huang–Rhys factor
The Huang–Rhys factor is a dimensionless parameter in solid-state and molecular spectroscopy that quantifies the strength of electron–phonon (vibronic) coupling during electronic transitions.
-
D.
The Nature of the Chemical Bond
The Nature of the Chemical Bond is a landmark chemistry book by Linus Pauling that systematically explains chemical bonding using quantum mechanics and became one of the most influential scientific texts of the 20th century.
-
E.
Feynman–Hellmann theorem
The Feynman–Hellmann theorem is a result in quantum mechanics that relates the derivative of an energy eigenvalue with respect to a parameter in the Hamiltonian to the expectation value of the corresponding derivative of the Hamiltonian.
- F. None of above. chosen
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
spectroscopic approximation
ⓘ
theoretical model in molecular spectroscopy ⓘ |
| addresses |
breakdown of purely electronic selection rules
ⓘ
coupling between electronic and vibrational motion ⓘ |
| allows |
non-zero intensity for electronically forbidden transitions
ⓘ
vibronically induced electronic transitions ⓘ |
| appliesTo |
electronic absorption spectra of molecules
ⓘ
electronic emission spectra of molecules ⓘ vibronic spectra ⓘ |
| assumes |
Born–Oppenheimer separation of electronic and nuclear motion as a starting point
ⓘ
electronic transition dipole moment depends on nuclear coordinates ⓘ |
| basedOn | expansion of transition dipole moment in normal coordinates ⓘ |
| category |
molecular physics concept
ⓘ
quantum mechanical approximation ⓘ spectroscopy ⓘ |
| contrastsWith | Condon approximation ⓘ |
| describes |
intensity borrowing in electronic transitions
ⓘ
intensity of vibronically allowed transitions ⓘ vibronic coupling ⓘ |
| enables | group-theoretical analysis of vibronically allowed transitions ⓘ |
| explains |
intensity of symmetry-forbidden transitions
ⓘ
weak absorption bands in electronic spectra ⓘ |
| field |
molecular quantum mechanics
ⓘ
molecular spectroscopy ⓘ quantum chemistry ⓘ |
| historicalContext | developed in mid-20th century molecular spectroscopy ⓘ |
| involves |
breakdown of the Condon approximation
ⓘ
first-order dependence of transition dipole on vibrational coordinates ⓘ |
| mathematicalForm | Taylor expansion of transition moment around equilibrium geometry ⓘ |
| namedAfter |
Edward Teller
ⓘ
Gerhard Herzberg ⓘ |
| refines |
Franck–Condon principle
ⓘ
surface form:
Franck–Condon approximation
Franck–Condon principle ⓘ |
| relatedTo |
Born–Oppenheimer approximation
ⓘ
non-adiabatic coupling ⓘ vibronic coupling theory ⓘ |
| relevantFor |
charge-transfer transitions
ⓘ
organic chromophores ⓘ polyatomic molecules ⓘ transition metal complexes ⓘ |
| usedFor |
assignment of vibronic structure in spectra
ⓘ
simulation of absorption band shapes ⓘ |
| usedIn |
analysis of vibronic progressions
ⓘ
calculation of transition intensities ⓘ computational spectroscopy ⓘ interpretation of molecular electronic spectra ⓘ |
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: Herzberg–Teller approximation Description of subject: 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.
Referenced by (3)
Full triples — surface form annotated when it differs from this entity's canonical label.
this entity surface form:
Herzberg–Teller expansion of transition moment