A quantum dynamics study of H2+OH→H2O+H employing the Wu-Schatz-Lendvay-Fang-Harding potential function and a four-atom implementation of the real wave packet method

We carry out numerous six-dimensional wave packet propagations for H-2+OH-->H2O+H on the ab initio based, Wu-Schatz-Lendvay-Fang-Harding potential energy function. For comparison, some calculations are also carried out on the older but more widely studied potential function of Walch, Dunning, Schatz, and Elgersma. The energy dependence of the total angular momentum J=0 cumulative reaction probability is obtained and J-shifting is used to estimate the bimolecular rate constant as a function of temperature. Some J>0 calculations are also carried out. A novel J-shifting procedure, designed to more accurately describe the effects of angular momentum, is introduced. We compare our results with transition state theory calculations and experiment. An important feature of our work is the development of an efficient, four-atom, parallel implementation of the real wave packet method, augmented with a recently developed finite difference method. (C) 2002 American Institute of Physics.