On the classical path method using Delves coordinates: Asymptotic solution for time-dependent amplitudes

An analytic perturbation series procedure is developed for evaluating transition amplitudes in an adiabatic basis throughout the asymptotic region of a molecular collision process described in Delves coordinates. This procedure is used in conjunction with the classical path method in a treatment of collinear atom-harmonic oscillator collisions. The importance of the new procedure in the application of the classical path method to reactive scattering is discussed.