Adsorption dynamics of H2 on Pd(100) from first principles

ARIEL LOZANO; AXEL GROß; HERIBERTO FABIO BUSNENGO

Santiago, Chile

Workshop; Latin American School On Computational Material Science; 2009

International Centre for Theoretical Physics (ICTP) y Universidad de Chile

We study H2 dissociative adsorption on Pd(100) through classical molecular dynamics (MD)calculations, using density functional theory (DFT) to describe the molecule–surface interaction potential. We employ two methods to evaluate the forces acting on the atoms along the trajectories: (i) by doing a DFT calculation every time step (AIMD), and (ii) by computing the gradient of a six-dimensional potential energy surface (PES) obtained first, by interpolation of DFT total energy results using the corrugation reducing procedure (CRP). The corresponding calculations, AIMD and CRP-PES-MD, respectively, provide very similar dissociative adsoption probabilities (Pdiss) as a function of the impact energy (Ei) for initial rotational states characterized by 0 ≤ J ≤ 4 indicating that the interpolated CRP-PES gives a faithful representation of the underlying ab initio PES.