Reduced dimensionality quantum calculations of mode specificity in OH+H2↔H2O+H

Abstract

We report reduced dimensionality quantum calculations for zero total angular momentum of the OH+H2↔H2O+H reaction using the Walch–Dunning–Schatz–Elgersma potential. The three bending degrees of freedom of the tetra-atomic system are treated adiabatically in the harmonic approximation. The full six-mode potential is minimized with respect to the bending degrees of freedom, and the dynamics of the three radial degrees of freedom is governed by an effective potential given by the sum of this minimized potential plus the local adiabatic bending energy. The Schrödinger equation for the radial degrees of freedom is solved using a modification of the hyperspherical approach, which we have described previously. Vibrational state-to-state reaction probabilities are presented for the ground and first excited bending states of H2O. We examine the effect of exciting the vibrations of H2, OH, and H2O on the reaction probability, and the results are compared qualitatively with experiments, and previous calculations.