Energy dependence of differential and integral cross sections for O(D1)+H2(υi=,ji=)→OH(υf,jf)+H reaction

Abstract

State-to-state differential and integral cross sections for the title reaction have been calculated using a dynamically exact quantum mechanical wave packet method on the ab initio ground H(2)O(X (1)A(')) electronic state potential energy surface of Dobbyn and Knowles. We focus on the energy dependence of the cross sections up to 0.15 eV. The total integral cross section and rate constant, obtained by summing the state-to-state integral cross sections over all open product rovibrational channels, are in excellent agreement with experimental measurements. Also in agreement with experimental data, the OH product is found to have highly inverted rotational state distributions and monotonically decaying vibrational state distributions. The calculated total differential cross section is roughly forward-backward symmetric, consistent with experimental data. The vibrational state-resolved differential cross sections are found to depend on the collision energy. The calculated results confirm the dominance of the insertion mechanism and provide a stringent test of the potential energy surface.