6-DIMENSIONAL QUANTUM DYNAMICS OF ADSORPTION AND DESORPTION OF H-2 ATPD(100) - STEERING AND STERIC EFFECTS

We report the first six-dimensional quantum dynamical calculations of dissociative adsorption and associative desorption. Using a potential energy surface obtained by density functional theory calculations, we show that the increase of the sticking probability with decreasing kin etic energy at low kinetic energies in the system H-2/Pd(100), which i s usually attributed to the existence of a molecular adsorption state, is due to dynamical steering. In addition, we examine the influence o f rotational motion and orientation of the hydrogen molecule on adsorp tion and desorption.