On the statistical mechanical interpretation of the translational energy dependence of rate processes

The rate coefficient for the rates of binary gas phase collision processes is expressed as an integral over the relative translational energy of the particles involved in a collision and as an integral over the energy of one of the particles. It is found that these representations of the rate coefficient provide two very different conceptual pictures of the translational energy dependence of rate processes. For systems with a disparate mass ratio (of the order of 10−2 to 10−1), it is found that the integration over the light particle energy coincides (approximately) with the integration over the relative energy.