Rotationally Inelastic Collision between Two Polar Molecules

Abstract

The rotational transitions in low energy collisions between two polar molecules are studied by two semiclassical methods. One method is the impact-parameter close-coupling (IPCC) method which is applied to the relatively high energy collisions. For the lower energy collisions, the perturbed rotational state (PRS) method is adopted within the framework of the semiclassical impact-parameter method. The intermolecular potential is approximated by the long range dipole-dipole interaction. By using these two approaches, rotational cross sections are evaluated over a wide velocity range for the first time. A scaling procedure is introduced to enable us to evaluate the cross sections for a wide variety of polarmolecule pairs which are not necessarily identical. The validity of the sudden approximation is also studied.