Statistical adiabatic channel model study of the H+O 2→HO 2 reaction on the lemon and hase potential energy surface

Abstract

The canonical statistical adiabatic channel model is used to calculate limiting high-pressure rate constants for the H+O 2→HO 2 reaction between 200 and 1000 K on the Lemon and Hase potential energy surface. An effective adiabatic channel potential which accounts for optimized matrix elements for the bending along the reaction path, non-separability of both the bending and HOO stretching modes, and of the J and K rotational quantum numbers is considered. The rate constant calculated at 300 K is about a factor of two smaller than a recent experimental value. An agreement better than 10% is obtained using a modified radial potential with no energy barrier for addition.