Effects of reactant rotational excitation on H + O-2 -> OH plus O reaction rate constant: quantum wave packet, quasi-classical trajectory and phase space theory calculations

We examine the impact of initial rotational excitation on the reactivity of the H + O-2 --> OH + O reaction. Accurate Chebyshev wave packet calculations have been carried out for the v(i) = 0, j(i) = 9 initial state of O-2 and the J = 50 partial wave. In addition, we present Gaussian- weighted quasi-classical trajectory and phase space theory calculations of the integral cross section and thermal rate constant for the title reaction. These theoretical results suggest that the initial rotational excitation significantly enhances reactivity with an amount comparable to the effect of initial vibrational state excitation. The inclusion of internally excited reactants is shown to improve the agreement with experimental rate constant.