A three-dimensional wave packet study of Ar⋯I2(B)→Ar + I + I electronic predissociation

A three-dimensional wave packet study of Ar⋯I2(B)→ Ar + I(2P3/2)+ I(2P3/2) electronic predissociation, arising from the argon-induced electrostatic coupling between the B(3Π0+u) and the repulsive a(3Π1g) state of I2, is presented. A time-dependent golden rule approach is used. The initial wave packet corresponds to a bound vibrational wave function of the Ar⋯I2(B) complex (with zero total angular momentum) multiplied by the electronic coupling. A 3-D propagation in the final dissociative surface is then performed and the predissociation rates are obtained by Fourier transform of the wave packet autocorrelation function. The potential energy surfaces are described by sums of atom-atom interactions. For the B(3Π0+u) state potential, empirically determined van der Waals parameters available from the literature are used. For the final dissociative a(3Π1g) electronic state, the van der Waals parameters are adjusted to reproduce the experimentally observed oscillations of the electronic predissociation rate as a function of the initial vibrational quantum number υ′ of I2. It is shown that good agreement between calculated and measured values can be obtained with a van der Waals well of 100 cm-1 and an interstate coupling of the order of 14 cm-1. © 1996 American Institute of Physics.We acknowledge support from the CNRS for the use of the computing facilities at IDRIS, and the European Community for visiting support ~SCT-CT91-0699!. One of us (O.R.) was supported by a grant from DGICYT No. PB92- 0053 and Comunidad Autónoma de Madrid No. 064/92.Peer Reviewe