Mixed quantum wave packet/classical trajectory treatment of the photodissociation process ArHCl→Ar+H+Cl

The photodissociation of HCl in the cluster Ar⋯HCl by an extremely short pulse was studied using a hybrid quantum mechanical/classical approach. In this method, the H atom is treated quantum mechanically, the heavy atoms classically, and the time-dependent self-consistent-field (TDSCF) approximation is used to couple the quantum with the classical modes. The results are compared with those of classical trajectory calculations. On the whole, good qualitative agreement is found between the results of the (partly quantum) hybrid method and the pure classical ones. However, quantum interference effects of quantitative significance are found both in the angular and in the kinetic energy distribution of the H atom product. These effects, and resonances that contribute to the process, are analyzed in terms of wave packets obtained for the H atom in the hybrid method. The usefulness and applicability of the hybrid method are discussed in the light of the results.