Atomic recombination dynamics on a solid surface: H2+W(001)

Abstract

A model potential to describe the interaction of a diatomic molecule with a rigid solid surface has been described previously. Using this interaction potential, a series of classical trajectory calculations have been carried out, designed to simulate the recombination dynamics of two hydrogen atoms initially adsorbed on a tungsten (001) solid surface to form a gas-phase hydrogen molecule. The vibrational and rotational state distributions of the desorbed hydrogen molecules are discussed in terms of a simple statistical model. The angular and speed distributions for the desorbed atoms and molecules are presented. The angular distributions are found to be substantially noncosine in form and peaked towards the surface normal, in qualitative agreement with experiment.