Newns-Anderson model of chemicurrents in H/Cu and H/Ag

The excitation of the electronic system induced by the adsorption of a hydrogen atom on the (1 1 1) surfaces of copper and silver is investigated using the time-dependent, mean-field Newns-Anderson model. Parameters for the model are obtained by fitting to density functional theory calculations, allowing the charge and energy transfer between adsorbate and surface to be calculated, together with the spectrum of electronic excitations. These results are used to make direct comparisons with experimental measurements of chemicurrents, yielding good agreement for both the magnitude of the current and the ratio of the currents for H and D adsorption. (C) 2008 Elsevier B.V. All rights reserved.