Russell–Saunders coupling
E251512
Russell–Saunders coupling is an atomic physics scheme that describes how individual electron orbital and spin angular momenta combine to determine the total angular momentum of an atom, especially in light atoms.
All labels observed (4)
| Label | Occurrences |
|---|---|
| Russell–Saunders coupling canonical | 5 |
| LS coupling | 1 |
| LS term coupling | 1 |
| LS-coupling Landé formula | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T2264860 — 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: Russell–Saunders coupling Context triple: [Henry Norris Russell, knownFor, Russell–Saunders coupling]
-
A.
Wigner–Eckart theorem
The Wigner–Eckart theorem is a fundamental result in quantum mechanics that factorizes matrix elements of tensor operators into a reduced matrix element and a purely geometric part given by Clebsch–Gordan coefficients, greatly simplifying angular momentum calculations.
-
B.
Zeeman effect
The Zeeman effect is the splitting of atomic or molecular spectral lines into multiple components when subjected to an external magnetic field, revealing information about energy levels and magnetic moments.
-
C.
Stark effect
The Stark effect is the splitting and shifting of atomic or molecular spectral lines caused by an external electric field.
-
D.
Sommerfeld fine-structure formula
The Sommerfeld fine-structure formula is a relativistic extension of the Bohr model that accurately predicts the fine-structure energy levels of the hydrogen atom.
-
E.
Bohr magneton
The Bohr magneton is a fundamental physical constant that represents the natural unit of the electron’s magnetic moment in atomic physics.
- 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: Russell–Saunders coupling Target entity description: Russell–Saunders coupling is an atomic physics scheme that describes how individual electron orbital and spin angular momenta combine to determine the total angular momentum of an atom, especially in light atoms.
-
A.
Wigner–Eckart theorem
The Wigner–Eckart theorem is a fundamental result in quantum mechanics that factorizes matrix elements of tensor operators into a reduced matrix element and a purely geometric part given by Clebsch–Gordan coefficients, greatly simplifying angular momentum calculations.
-
B.
Zeeman effect
The Zeeman effect is the splitting of atomic or molecular spectral lines into multiple components when subjected to an external magnetic field, revealing information about energy levels and magnetic moments.
-
C.
Stark effect
The Stark effect is the splitting and shifting of atomic or molecular spectral lines caused by an external electric field.
-
D.
Sommerfeld fine-structure formula
The Sommerfeld fine-structure formula is a relativistic extension of the Bohr model that accurately predicts the fine-structure energy levels of the hydrogen atom.
-
E.
Bohr magneton
The Bohr magneton is a fundamental physical constant that represents the natural unit of the electron’s magnetic moment in atomic physics.
- F. None of above. chosen
Statements (46)
| Predicate | Object |
|---|---|
| instanceOf |
LS coupling
ⓘ
atomic coupling scheme ⓘ concept in atomic physics ⓘ |
| alsoKnownAs |
LS coupling
ⓘ
linked to:
Russell–Saunders coupling
|
| appliesTo |
light atoms
ⓘ
many-electron atoms ⓘ |
| assumes |
coupling of individual electron orbital angular momenta to form L
ⓘ
coupling of individual electron spins to form S ⓘ electron–electron Coulomb interaction dominates spin–orbit coupling ⓘ spin–orbit interaction is weak compared to electrostatic interaction ⓘ subsequent coupling of L and S to form J ⓘ |
| basedOn | vector addition of angular momenta ⓘ |
| category |
atomic structure theory
ⓘ
spectroscopy ⓘ |
| contrastedWith |
intermediate coupling schemes
ⓘ
jj coupling ⓘ |
| defines |
multiplicity 2S+1
ⓘ
orbital term letter L = S, P, D, F, ... ⓘ total angular momentum quantum number J ⓘ |
| describes |
coupling of orbital and spin angular momenta of electrons
ⓘ
formation of total angular momentum J ⓘ formation of total orbital angular momentum L ⓘ formation of total spin angular momentum S ⓘ |
| field | atomic physics ⓘ |
| governs | Hund’s rules for ordering of terms ⓘ |
| hasNotation | term symbol 2S+1L_J ⓘ |
| lessAccurateFor | heavy atoms ⓘ |
| namedAfter |
Frederick Albert Saunders
ⓘ
Henry Norris Russell ⓘ |
| relatedConcept |
Hund’s rules
ⓘ
linked to:
Hund’s rules for ordering of terms
jj coupling ⓘ spin–orbit coupling ⓘ term symbols in atomic spectroscopy ⓘ |
| relatesTo |
LS term coupling
ⓘ
linked to:
Russell–Saunders coupling
fine-structure splitting ⓘ selection rules in atomic spectroscopy ⓘ |
| usedFor |
classification of atomic energy levels
ⓘ
derivation of atomic term symbols ⓘ description of fine structure in atomic spectra ⓘ spectroscopic notation of atomic states ⓘ |
| usedIn |
analysis of optical spectra of atoms
ⓘ
construction of atomic level diagrams ⓘ |
| usesQuantumNumber |
total angular momentum quantum number J
ⓘ
total orbital angular momentum quantum number L ⓘ total spin quantum number S ⓘ |
| validWhen | spin–orbit coupling is a small perturbation ⓘ |
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: Russell–Saunders coupling Description of subject: Russell–Saunders coupling is an atomic physics scheme that describes how individual electron orbital and spin angular momenta combine to determine the total angular momentum of an atom, especially in light atoms.
Referenced by (8)
Full triples — surface form annotated when it differs from this entity's canonical label.
linked to: Russell–Saunders coupling
linked to: Russell–Saunders coupling
linked to: Russell–Saunders coupling