Vibrational predissociation of van der Waals complexes:: Quasi-classical results with Gaussian-weighted trajectories

A detailed application of the Gaussian-weighted trajectory method to the photodissociation of the Rg center dot center dot center dot Br-2 (Rg = He, Ne, Ar) van der Waals triatomics is presented. In agreement with previous applications on molecular collisions, the approach significantly enhances the quasi-classical predictions of product state distributions with respect to those obtained with the Standard Binning procedure, especially near a vibrational channel closing. The different molecules studied shed light on the sort of improvement to expect for various densities of vibrational quantum-states involved in the fragmentation process. Extension to larger polyatomic molecules, its possible difficulties and solutions are briefly sketched. (c) 2008 Elsevier B.V. All rights reserved.