Resonant Transfer of Vibrational Energy in Molecular Collisions

The cross section for resonant vibration—vibration energy exchange between infrared-active molecules due to the long-range dipole potential is formulated. It is found that despite certain restrictions imposed by rotational selection rules, energy-exchange cross sections may be as much as 0.01 to 0.1 times as large as the molecular gas-kinetic cross section and are greater than those estimated using only an exponential repulsive interaction between molecules.