Scattering matrix determination by asymptotic analysis of complex scaled resonance wave functions: Model Cl+H-2 nonadiabatic dynamics

It has previously been shown that partial widths of resonance states can be calculated by the asymptotic analysis of the complex scaled resonance wave function [U. Peskin, N. Moiseyev, and R. Lefebvre, J. Chem. Phys. 92, 2902 (1990)] and by the complex coordinate scattering theory [N. Moiseyev and U . Peskin, Phys. Rev. A 42, 255 (1990)]. Here we use these methods for the f irst time to calculate complex partial width amplitudes. The complex amplit udes are independent of the complex scaling parameters and are used for cal culating the resonance contribution to the scattering matrix (the S matrix) in the case of Cl + H-2 scattering described by two coupled one-dimensiona l potential energy curves. The background contribution to the S matrix was calculated by the use of one ClH2 potential energy curve only. The sum of t he resonance and the background contributions provides accurate complex S m atrix elements and transition probabilities, even at the resonance energy f or which total reflection is obtained due to the interference between the t wo contributions. (C) 1999 American Institute of Physics. [S0021-9606(99)00 640-6].