Time-dependent wave packet calculations on parallel computers:: A new and efficient algorithm for evaluating (H)over-cap Ψ

A general parallel method for evaluating the action of the Hamiltonian operator on the wave function for use in time-dependent quantum mechanics is presented. In this algorithm the wave function is distributed over the processors of a parallel machine according to two different degrees-of-freedom. so that each processor holds two different slices of the same wave function. This leads to very efficient communication and computation characteristics of the algorithm. The algorithm is implemented for a gas-surface reactive system for two different communication protocols. Timings are presented and the scaling of the algorithm is discussed for each of the implementations. Finally, extensions of the algorithm are discussed. (C) 2001 Elsevier Science B.V. All rights reserved.