Interference between vibration-to-translation and vibration-to-vibration energy transfer modes in diatomic molecules at high collision energies

Abstract

An explicit time dependent approach for simultaneous VT and VV energy transfer in diatom–diatom collisions is explored using the exponential form of ladder operators in the solution of the Schrödinger equation of motion. The collision of two hydrogen molecules is chosen to illustrate the extent of interference between VT and VV modes among various vibrational states. While vibrational energy transfer processes of nominally VT type can be treated with pure VT mode at low collision energies, the intermode coupling is found to be very important at collision energies of several ℏω. The occurrence of the coupling appears to be nearly universal in vibrational transitions at such energies. Exceptions to the coupling have been discussed.