Rotational quantum dynamics in a non-activated adsorption system

Abstract

The effect of the rotational dynamics on the dissociation of hydrogen on Pd(100) has been studied by three- and five-dimensional quantum dynamical coupled-channel calculations. We have used a model potential energy surface with features derived from ab initio calculations. In particular, we have focused on the effect of the change of the hydrogen bond length upon adsorption and desorption which leads to a non-monotonic behaviour both in the sticking probability as well as in the rotational alignment in desorption as a function of the rotational quantum number, thus explaining recent experimental results. In addition, we have analysed the effect of the surface corrugation and the influence of the isotope on the rotational alignment in desorption.