NON-ARRHENIUS RATE CONSTANTS

A simple and accurate formula is derived for the non-Arrhenius rate constant as a function of the Arrhenius rate constants, the concentrations of the species present, the temperature, the source energy of the hot atoms, and other parameters of the system. In the limiting cases where the source energy of the hot atoms is relatively low, the temperature is relatively high, or the concentration of the moderator is relatively high, the formula for the non-Arrhenius rate constant reduces to that of the Arrhenius rate constant, as expected. The validity of the formula for the non-Arrhenius rate constant was confirmed by comparing its results with those obtained from a detailed solution of the Boltzmann equation and a Monte Carlo simulation.