Three-dimensional wavepacket study of the reaction OH + H2 → H2O + H: a mixed quantal/classical approach Original Research Article

A semiclassical wavepacket method is presented for diatom-diatom scattering of the type AB+CD → ABC+D; ABD+C in which the vibrational motions of the two reagent molecules as well as their relative translational motion are treated quantum mechanically and rotational motions classically. The method is an extension of a recently reported study in which only vibrational motions of the reagent molecules were treated quantum mechanically. As before, the coupling between the quantal and classical degrees of freedom is achieved through a semiclassical effective Hamiltonian, which governs the classical trajectories. The methodology is illustrated by computing initial state-selected total reaction probabilities for the title reaction. Comparisons of reaction probabilities are made with those of recently reported five- and six-dimensional quantal calculations as well as those obtained from our previous version of the method.