The Dynamics of Xbc Van Der Waals Complexes: Fragmentation Mechanisms in Neon Chloride, Helium Chloride, Neon Iodine Chloride, Helium Iodine Chloride

Three dimensional time-dependent quantum calculations are presented for the van der Waals vibrational predissociation reactions of NeCl_2, HeCl _2, NeICl, and HeICl. The method employed (Gray and Wozny, J. Chem. Phys., 1989, 91, 7671) is an iterative solution of the time-dependent Schrodinger equation using a Kosloff-Kosloff propagation on a basis set expansion of the internal degrees of freedom. The results for these systems agree with experiment and other time-independent quantum calculations, where available. The similarities and differences between the four systems are explored by detailed inspection of the propagating wavefunction in radial and angular dimensions. Lifetimes and rotational product distributions can be understood in terms of a unified fragmentation mechanism that depends on the convolution of the initially prepared state with potential coupling, and short time dynamics. The potential coupling can be understood in terms of a classical force field, and the short time dynamics can be approximated by classical trajectories in all four cases.