Ab initio simulation of copper and silver adsorption on the MgO(1 1 1) surface

Density functional theory calculations using ab initio pseudopotentials and a plane wave basis are applied to study copper and silver overlayers on the unreconstructed MgO(1 1 1) surface. Each of the two adsorbates can stabilize both O- and Mg-terminations of MgO(1 1 1). We found zero charge transfer for noble metals adsorption on the Mg-terminated surface. A non-zero charge transfer, which occurs at the oxygen terminated surface, is not sufficient to induce an energy gap at the Fermi level and to convert the surface into insulating one.