Hund’s rules for ordering of terms

Target entity: Hund’s rules for ordering of terms
Context triple: [Russell–Saunders coupling, governs, Hund’s rules for ordering of terms]

• A. Russell–Saunders coupling
  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.
• B. 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.
• C. Slater-type orbital basis sets
  Slater-type orbital basis sets are mathematical functions used in quantum chemistry to approximate atomic orbitals with realistic radial behavior, particularly in early and conceptual implementations of electronic structure methods.
• D. Sommerfeld quantization rules
  Sommerfeld quantization rules are an early quantum theory refinement of Bohr’s model that quantize electron motion in elliptical orbits using action integrals, helping to explain fine-structure details in atomic spectra.
• E. Rydberg–Ritz combination principle
  The Rydberg–Ritz combination principle is a rule in atomic spectroscopy stating that the frequencies (or wavenumbers) of spectral lines can be expressed as differences between terms in a series, enabling systematic prediction and classification of atomic spectra.
• F. None of above. chosen
• G. Unsure - the case is ambiguous/there is not enough information to decide.

Target entity: Hund’s rules for ordering of terms
Target entity description: Hund’s rules for ordering of terms are empirical guidelines in atomic spectroscopy that predict the relative energies and ground-state term of an atom by specifying how electron spins and orbital angular momenta combine under LS (Russell–Saunders) coupling.

• A. Russell–Saunders coupling
  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.
• B. 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.
• C. Slater-type orbital basis sets
  Slater-type orbital basis sets are mathematical functions used in quantum chemistry to approximate atomic orbitals with realistic radial behavior, particularly in early and conceptual implementations of electronic structure methods.
• D. Sommerfeld quantization rules
  Sommerfeld quantization rules are an early quantum theory refinement of Bohr’s model that quantize electron motion in elliptical orbits using action integrals, helping to explain fine-structure details in atomic spectra.
• E. Rydberg–Ritz combination principle
  The Rydberg–Ritz combination principle is a rule in atomic spectroscopy stating that the frequencies (or wavenumbers) of spectral lines can be expressed as differences between terms in a series, enabling systematic prediction and classification of atomic spectra.
• F. None of above. chosen