The electronic structure of the c(2 x 2) and the missing row (2√2 x √2)R45° phases of chemisorbed O on Cu(001) at a coverage of 0.5 monolayers was calculated using a full-potential semi-infinite embedding technique. Calculations were made over a range of Cu–O layer spacings, and from the change in the work function, the effective charge on O was obtained. The effective charge was the same for both phases of the O/Cu(001) surface with a value of −0.3|e| on O, and consequently too small to drive any surface instability. The angular momentum-resolved density of states and energy-resolved charge densities were used to describe the binding and the spatial electronic overlap at the surfaces. In the reconstructed (2√2 x √2)R45° phase the O and the surface Cu atoms underwent displacements, which optimised the bonding.

Electronic Structure and Surface Reconstruction of Adsorbed Oxygen on Copper(001). I.Merrick, J.E.Inglesfield, H.Ishida: Surface Science, 2004, 551[3], 158-70