Trajectory-based modelling of the quantum dynamics of vibrational predissociation: Application to the Ar [formula omitted] complex

Abstract

The quantum dynamics of vibrational predissociation of the Ar ⋯Br2 triatomic molecule is described within a trajectory-based framework. The Br2 stretching mode is mapped into a set of classical (coupled) harmonic oscillators, associated to each vibrational state of the diatomic molecule. The time evolution of the molecular wave packet along the dissociation coordinate is described within the hydrodynamical formulation of quantum mechanics, specifically using the interacting trajectory representation. The relatively small number of interacting trajectories required to attain numerical convergence (N=100), makes the present model very appealing in comparison with other trajectory-based methods. The underlying parameterisation of the density was found to represent accurately the evolution of the projection of the molecular wave packet along the van der Waals mode, from the ground vibrational state into the continuum. The computed lifetime of the predissociating level and the population dynamics are in very good agreement with those observed experimentally.