APPLICATION OF AN EFFICIENT ASYMPTOTIC ANALYSIS METHOD TO MOLECULE-SURFACE SCATTERINGE

An improved method for performing asymptotic analysis developed by Balint-Kurti et al. [J. Chem. Sec. Faraday Trans. 86, 1741 (1990)] was used with the close-coupling wave packet (CCWP) method. S-matrix elements are computed from the time dependence of the wave packet amplitude at a dividing surface in the asymptotic region. The analysis technique can be combined in a natural way with the use of an optical potential to absorb the scattered wave function beyond the dividing surface and with a technique in which the initial wave function is brought in on a separate, one-dimensional grid, thereby allowing the use of a smaller grid. The use of the method in conjunction with the Chebyshev and short-iterative Lanczos propagation techniques is demonstrated for a model problem in which H-2 is scattered from LiF(001). Computed S-matrix elements an in good agreement with those obtained using a time-independent close-coupling method. (C) 1995 American Institute of Physics.