The Born-Oppenheimer approximation and matrix elements of terms in the effective molecular Hamiltonian that violate the BO approximation. Vibration, rotation, spin-orbit, interelectronic interaction. Hund's coupling cases.

All coupling processes are mediated by vibrational overlap integrals, which are computed numerically. Semiclassical calculation of overlaps reveals physical factors controlling computed values...

Introduction to dynamical processes.