A Simple Dissipation Model for Collisional T‐V Energy Transfer and Association Processes between Atoms and Polyatomic Molecules. I. Analytical Approximations for the Case of a Morse Interaction

A simple classical phenomenological Markoffian damping model for the collisional T‐V energy transfer of a gas atom impinging on a “surface”‐atom of a polyatomic molecule or a solid lattice surface is proposed. The relevant dynamical features of the polyatomic system, projected onto the collisional axis, are taken to be reduced to a local (surface oscillator) and to a dissipating (damping) part. In the context of a new approximate renormalizing procedure for the calculation of T‐V energy transfer, analytical results were derived for the case of a intermolecular Morse potential in a wide velocity range. We have shown that the existence of a V‐V intramolecular dissipative mechanism can strongly influence the velocity dependence on the energy transfer. Different effects due to the intermolecular dissipating forces were observed for the energy transfer in the impulsive and languid collisional regime.