Theory of chemisorption

We determine the electronic structure of a semiinfinite crystal with a general coverage by adatoms, if there exists a partial order described by the long-range order parameter5. The tight-binding formalism is used, the presence of the surface is included via the surface Green function method, and the effect of disorder is described by a version of the coherent potential approximation. The local densities of states at/near the surface as well as the interaction energy of adatoms are calculated as functions of the coverage, and the long-range order parameterS. The numerical examples modelling the cases of a gas adsorption on the transition metal surfaces as well as the transition metal atoms on the transition metal surfaces, are investigated.