Quantal trajectories for adiabatic and nonadiabatic regimes of vibronic systems

Abstract

Exact and averaged nuclear pseudorotational quantal trajectories are compared for various adiabatic and vibronic states of the Longuet-Higgins E⊗ϵ Jahn–Teller model. It is argued that the usual averaging over the electronic motion could be understood as being a consequence of ergodicity. The failure of the Born–Oppenheimer factorization to obey the ergodic hypothesis was examined. A quantitative separation of the electronic and nuclear time-scales is, nevertheless, achieved for all regimes. It is shown that the short-time deviations from the global “drift” of the electronic and nuclear motions are perfectly correlated. ©1999 John Wiley & Sons, Inc. Int J Quant Chem 75: 409–416, 1999