QUANTUM CALCULATIONS OF INELASTIC-SCATTERING OF HCN AND HNC BY AR

A quantum scattering calculation of collision cross-sections and energ y transfer of HCN and HNC in collisions with Ar is reported. The HCN ( HNC) rotation is treated in the infinite order sudden approximation, a nd the HCN (HNC) vibrations are treated by the coupled-channel method. A sum of two-body Lennard-Jones potentials is used to describe the Ar -HCN/HNC interaction, and the HCN/HNC intramolecular potential is a gl obal fit to extensive, high quality ab initio calculations. Vibrationa l state-to-state cross-sections and state specific energy transfer for HCN and HNC states are calculated as functions of initial relative tr anslational energy.