Model Analysis of Rotationally Inelastic Ar + H2O Scattering in an Electric Field

Abstract

We develop an analytic model of thermal state-to-state rotationally inelastic collisions of asymmetric-top molecules with closed-shell atoms in electric fields and apply it to the Ar−H2O collision system. The predicted cross sections as well as the steric asymmetry of the collisions show at fields up to 150 kV/cm characteristic field-dependent features which can be experimentally tested. Particularly suitable candidates for such tests are the 000 → 220 and 101 → 221 channels, arising from the relaxation of the field-free selection rules due to the hybridization of J states by the field. Averaging over the M′ product channels is found to largely obliterate the orientation effects brought about by the field.