Triple

Target entity: Born–Oppenheimer approximation
Context triple: [Condon–Morse potential, relatedTo, Born–Oppenheimer approximation]

• A. Born–Oppenheimer approximation chosen
  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. 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. Franck–Condon principle
  The Franck–Condon principle is a rule in molecular spectroscopy that explains the intensity distribution of vibronic transitions by assuming electronic transitions occur much faster than nuclear motion, making vertical transitions between vibrational states most probable.
• D. 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.
• E. Hartree–Fock method
  The Hartree–Fock method is an approximate quantum mechanical approach for determining the electronic structure of atoms, molecules, and solids by modeling electrons as occupying self-consistent single-particle orbitals.
• F. None of above.
• G. Unsure - the case is ambiguous/there is not enough information to decide.