A tight-binding version of the linear-muffin-tin-orbital method is used to describe the electronic structure of random overlayers on a perfect substrate in a self-consistent manner within the local-density approximation. The true semi-infinite nature of the system is incorporated via the surface-Green’s-function approach. A generalization of the coherent-potential-approximation method to treat inhomogeneous alloys is used to study the effect of disorder. The formalism is applied to evaluate the layer-projected densities of states and work functions of random Ag-Pd overlayers on a fcc Ag(001) substrate.

• Received 16 March 1992

DOI:https://doi.org/10.1103/PhysRevB.46.4222