Video Lectures

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.

SES # TOPICS
1

Introduction to the Spectroscopic Effective Hamiltonian (01:19:04)

Description

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.

2

Spectroscopic Pertubations, Predissociation, and Autoionization (01:11:24)

Description

Introduction to dynamical processes.

3

Semiclassical Methods for Calculating Vibrational Overlap Integrals (01:04:46)

Description

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.

4

Wavepackets and Landau-Zener (01:31:55)

Description

What happens in the vicinity of a curve crossing?