The quantum distribution of initial conditions suggested recently by Careless and Hyatt as a means of "phase-averaging" classical trajectories is shown to lead to reaction probabilities which depend on the initial distance between the reagents even when this distance is sufficiently large for the corresponding interaction energy to vanish. We used that distribution to calculate reaction probabilities for the collinear H + H2 exchange reaction on a potential energy surface for which quasi-classical and exact quantum results had been previously obtained. The dependence of the resulting reaction probabilities on the arbitrarily chosen value of the initial atom-molecule separation was substantial. We conclude that the use of such quantum distributions for initial conditions is physically unacceptable.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Condensed Matter Physics
- Atomic and Molecular Physics, and Optics
- Surfaces and Interfaces