Generalized Chemistry–Internal Energy Coupling Model Using Prior Recombination Distribution

Abstract

In this work, the interaction between the internal energy states and the dissociation/recombination process for a diatomic molecule is studied in detail. In particular, the state-specific recombination and dissociation rate constants are derived as a function of internal energy distribution and other molecular parameters. As a special case, applying this result with specific vibrational energy distributions, we obtain the classic Marrone and Treanor models. An information theory approach to obtain the initial recombination distribution for any diatomic molecule is also presented. The general idea is to incorporate the vibrational and the rotational effects in the dissociation and recombination process without a full vibrational-rotational state-specific model. The effect of this rovibrational coupling is to produce an initial recombination distribution that is biased to the high internal energy states. These initial recombination distributions are then thermally averaged to obtain temperature-dependent expressions for different diatomic molecules to characterize the internal energy distribution of recombining molecules.