Hybrid quantum/classical studies of photodissociation and recombination of I2 (A) in rare gas matrices: A linear chain model

Abstract

A hybrid quantum/classical model is developed for the photodissociation and recombination dynamics of an I2 molecule in low-temperature rare-gas (Rg) matrices. The simplified model consists of an I2 molecule embedded in a linear chain of Rg atoms. The aggregate is partitioned into a quantum system and a classical bath, which are self-consistently coupled. Two partitioning schemes are used. The first treats the I-I coordinate quantum mechanically and the Rg coordinates classically. The second and more reliable scheme includes in the quantum system both the I-I mode and the symmetric motion of the two nearest Rg atoms. Both models show substantial energy transfer from the dissociating I2 to the solvent, followed by coherent vibrational motion of the recombined I2. It is found that the one-dimensional quantum/classical scheme is consistent with its higher dimensional counterpart, although the latter shows much faster dephasing. © 1996 John Wiley & Sons, Inc.