Application of the semiclassical initial value representation and its linearized approximation to inelastic scattering

The semiclassical (SC) initial value representation (IVR), and its linearized approximation (LA), have been applied to the well-studied Secrest-Johnson model of colinear He + H-2(v(i)) --> He + H-2(v(f)) vibrationally inelastic scattering. The full SC-IVR treatment describes the quantum interference structure in the vibrational transition probabilities quantitatively, while the LA version does so only very qualitatively. This is consistent with earlier work on time correlation functions which found that the LA was able to describe quantum effects accurately in the short time dynamics, but not quantum coherence effects in the longer time dynamics. (C) 1999 Elsevier Science B.V. All rights reserved.