Microcanonical rate constant in nonequilibrium distribution of vibrational energy on the basis of Slaterʹs theory of unimolecular reactions Original Research Article

A model based on Slaterʹs treatment about uncoupled harmonic oscillators has been developed toward strong couplings, allowing intramolecular vibrational energy redistribution (IVR) fast enough to justify the averaging over the states involved in IVR. There are possibilities of taking into account the nonequilibrium distributions of energy among normal modes with different effective temperatures on each oscillator on this model. Computational results imply that there exist such distributions which increase the rate constant by several orders of magnitude. The effect of the restricted IVR was considered and also found to increase the rate constant; as well as the dependence of the IVR from the vibrational anharmonicity is taken under discussion.