Multiple configuration quantum/classical treatments of reaction dynamics

The accuracy of quantum/classical approaches for studies of reaction dynami cs is investigated through simulations of the collinear and J=0 dynamics of the O(P-3)+HCl reaction on two potential surfaces. The results of classica l and two types of quantum/classical treatments of this reaction are compar ed to the results of quantum wave packet simulations. It is found that the accuracy of the single configuration quantum/classical treatment is sensiti ve to features of the potential surface. Most of this sensitivity is remove d when a second configuration is introduced. For collision energies below 0 .8 eV, the multiple configuration quantum/classical treatment provides reac tion probabilities and product state distributions that are in good agreeme nt with the results of the corresponding quantum simulation. The agreement deteriorates at higher collision energies, but here the agreement between t he quantum and classical results is quite good. (C) 2000 American Institute of Physics. [S0021-9606(00)00143-4].