State-to-state rate constant calculations for V-V energy transfer in CO-N2 collisions

Single and multiquantum vibrational relaxation of low and highly vibrationally excited levels of CO in collisions with N2 is studied within the semiclassical coupled state method. The dynamics is followed using ab initio interaction potential for the short-range interaction and updated multi-pole expansions for the long range interaction. Compared to the previous study, a better agreement with the available experimental rate constants is obtained, particularly in the critical low temperature regime down to T=80K. Remarkable corrections are found for rate constants for single and multi-quantum transitions between highly excited CO and N2 molecules.