PERFORMANCE OF CLOSE-COUPLED WAVE-PACKET METHODS FOR MOLECULE-CORRUGATED SURFACE SCATTERING

The H-2 + LiF(001) system was used to investigate the performance of t he hybrid close-coupling wave packet (CCWP) method and of a symmetry a dapted, fully close-coupled wave packet (SAWP) method for a molecule-s urface problem characterized by fairly high corrugation. In the calcul ations, a realistic, phi-dependent model potential was used. The calcu lations were performed for a collision energy of 0.2 eV, with H-2 init ially in its j=0 rotational state at normal incidence to the surface, Large increases in the computational efficiencies of both wave packet methods were achieved by taking advantage of the potential coupling ma trices associated with both methods becoming sparser with increasing m olecule-surface distance. For the present model problem and employing this increased sparseness at longer range, the SAWP method is faster t han the CCWP method by a factor of 2. The potential usefulness of the SAWP method for dissociative chemisorption problems is discussed. (C) 1995 American Institute of Physics.