Effect of surface motion on the rotational quadrupole alignment parameter of D2 reacting on Cu(111)

Ab initio molecular dynamics (AIMD) calculations using the specific reaction parameter approach to density functional theory are presented for the reaction of D2 on Cu(111) at high surface temperature (T(s)=925  K). The focus is on the dependence of reaction on the alignment of the molecule's angular momentum relative to the surface. For the two rovibrational states for which measured energy resolved rotational quadrupole alignment parameters are available, and for the energies for which statistically accurate rotational quadrupole alignment parameters could be computed, statistically significant results of our AIMD calculations are that, on average, (i) including the effect of the experimental surface temperature (925 K) in the AIMD simulations leads to decreased rotational quadrupole alignment parameters, and (ii) including this effect leads to increased agreement with experiment.

High-dimensional quantum dynamical study of the dissociation of H2 on Pd(110)

We report the first six-dimensional quantum dynamical study of the dissociative adsorption of H(2) on a (110) surface. We have performed quantum coupled-channel calculations for the system H(2)/Pd(110) based on a potential energy surface (PES) that was derived from ab initio electronic structure calculations. In particular, we have focused on the effects of the corrugation and anisotropy of the PES on the H(2) dissociation probability. Our results agree well with the available experimental data for the sticking probability as a function of the initial kinetic energy and the angle of incidence. Because of the coupling between the anisotropy and corrugation of the potential energy surface our calculations predict an unusual rotational heating and a rather small rotational alignment in desorption.