Calculated surface segregation in transition metal alloys

We outline a combination of numerical techniques which recently has been us ed to calculate heats of solution, surface energies and segregation energie s for a large number of metals and alloys. The basic ingredients are densit y functional theory, a Green's function approach to the one-electron proble m formulated within a linear muffin-tin orbitals basis, the coherent potent ial approximation corrected for charge transfer effects by the screened imp urity model, and the atomic sphere approximation corrected for the higher m ultipoles of the charge density. We discuss the accuracy of the combined nu merical technique and present results for the surface segregation of single impurities, the stability of pseudomorphically grown overlayers on Ni, and segregation profiles in Rh75Pt25. (C) 1999 Elsevier Science B.V. All right s reserved.