Quantum mechanical study of vibrational energy transfer in Ar-O3 collisions: influence of symmetry.

The vibrational energy transfer in Ar-O(3) collisions is investigated within the breathing sphere approximation. Ozone wave functions are calculated with a simplified potential energy surface and used in the close coupling scattering equations. Inelastic transition probabilities are determined for all bound states of O(3). Energy transfer is studied in one asymmetric, (16)O(16)O(18)O, and two symmetric isotopomers, (16)O(16)O(16)O and (16)O(18)O(16)O. Two measures of the energy transfer are considered: Microcanonical deactivation for a fixed collision energy and thermal vibrational relaxation described by the master equation at a fixed temperature. In either case, the energy transfer is symmetry independent near the dissociation threshold and the sensitivity to symmetry grows as the ozone energy decreases.