Breakdown of the Born-Oppenheimer Approximation in Diatomic Molecules
Lectures by Professor Robert Field
This lecture series was offered during January 2005 as a follow-up to topics covered in 5.74. Attendance was voluntary and open to any students with a background in quantum mechanics (5.61 or equivalent) and an interest in molecular dynamics.
Lecture 1: Introduction to the Spectroscopic Effective Hamiltonian
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.
Lecture 2: Spectroscopic Pertubations, Predissociation, and Autoionization
Introduction to dynamical processes.
Lecture 3: Semiclassical Methods for Calculating Vibrational Overlap Integrals
All coupling processes are mediated by vibrational overlap integrals, which are computed numerically. Semiclassical calculation of overlaps reveals physical factors controlling computed values: the length of the stationary phase region is controlled by the slopes of the potential curves at the intersection and the velocity in the crossing region.
Wavepackets and Landau-Zener (01:31:55)
Lecture 4: Wavepackets and Landau-Zener
What happens in the vicinity of a curve crossing?