Initial value representation for the classical propagator and S-matrix with the help of coherent states

This Letter demonstrates how coherent states can be used to construct an initial value representation for the propagator and classical S -matrix. Advantage is taken of the fact that the coherent state `coordinate' describes trajectories in phase space, resulting in an unusual structure for the propagator. The method, which avoids the usual stability analysis, is successfully applied to nonreactive atom–diatom scattering.