Vibration–rotation relaxation in bimolecular collisions with application to para-hydrogen

Abstract

Three‐dimensional quantum mechanical calculations in the effective potential approximation have been made on the para‐hydrogen system. At low temperatures, vib–rotationally inelastic collisions were examined while breathing sphere calculations were used to probe the high‐temperature regime. It was found that simultaneous vibrational and rotational processes contribute to the overall mechanism of vibrational relaxation. Collisionally induced intra‐ and intermolecular energy transfer is possible in the present calculation, and the corresponding cross sections are examined in detail. Rates are calculated from the cross sections and compared with experiment.