CALCULATION OF COLLISIONAL-ENERGY-TRANSFER RATES IN HIGHLY EXCITED MOLECULES

Expressions are deduced to enable the mean energy transferred in collisions between a highly excited molecule and a bath gas to be obtained economically from trajectory calculations. To relate experimental and theoretical results, it is shown that the quantity of interest is the distribution function for the rate of energy transfer (or its moments), rather than that for the energy transferred per collision. The latter is related to the rate by a collision number Z (or collision frequency ω) whose definition is arbitrary. This enables theory and experiment to be compared without the artifactual removal of the "elastic peak" in the energy-transfer distribution which has caused problems in the past. © 1990 American Chemical Society.