Investigation of time-dependent semiclassical methods for scattering calculations

The semiclassical wave packet approach to collision theory is investigated using a propagation method derived from the time-dependent variational principle of Dirac, Frenkel and McLachlan. The test system used is the collinear He + H2 model for inelastic scattering. The time-dependence of the gaussian wave packet parameters is analysed and comparison is made with the simpler quantum trajectory propagation method of Heller. Transition probabilities are found to be improved by the variational method. Preliminary investigations of a reactive system are discussed and arguments for further directions in developing the theory are given.