Density functional theory calculations of adsorption-induced surface stress changes

Density functional theory calculations of adsorbate-induced surface stress changes have been performed for a number of adsorbate and overlayer systems for which experimental data exists, namely: oxygen and sulphur adsorption on Ni(1 0 0); oxygen adsorption on W(1 1 0); pseudomorphic growth of Ni on Cu(1 0 0) and of Fe on W(1 1 0); oxygen adsorption on a 5 ML pseudomorphic film of Ni(1 0 0) grown on Cu(1 0 0). The theoretical calculations reproduce all the qualitative features of the experimental data, but there are some significant quantitative differences, most notably for the two atomic adsorbates on the bulk Ni(1 0 0) surface, for which the theoretical stress changes are substantially smaller than the experimental ones, a situation not obviously attributable to experimental error. For the W(1 1 0)/Fe system there is also a marked difference between experiment and theory in the coverage at which key surface stress changes occur.