A LINEAR-CHAIN HYBRID QUANTUM/CLASSICAL MODEL FOR THE PHOTODISSOCIATION AND RECOMBINATION OF I-2(A) IN RARE-GAS MATRICES

The photodissociation and subsequent recombination of I-2(A) in low temperature Ar or Kr matrices are investigated theoretically in a one-dimensional model. The dynamics of the I-2 molecule, which is embedded in a Linear chain of rare gas atoms, is explicitly treated with time-dependent quantum mechanics, while the motion of the bath atoms is described by classical trajectories. The quantum subsystem is self-consistently coupled with the classical bath via time-dependent mean fields. Our calculations show substantial energy transfer from the dissociating iodine to the solvent, and subsequent energy propagation in the solvent. The results indicate that coherence in the recombined I-2 wave packet is not completely destroyed, in agreement with experiment and previous simulations. The temperature and wavelength dependence of the dynamics are also investigated. (C) 1995 American Institute of Physics.