AB-INITIO CALCULATIONS OF THE ELECTRONIC AND ATOMIC-STRUCTURE OF SOLIDS AND THEIR SURFACES

We briefly review an ab-initio Green function method for the calculati on of the electronic structure of disordered alloys and their surfaces based on the local (spin) density approximation and the all-electron tight-binding linear muffin-tin orbital method. The semi-infinite geom etry is incorporated via the surface Green functions and the coherent potential approximation (CPA) is used to treat the alloy disorder. The electronic structure serves as an input for the first-principles stud ies of the phase stability of metallic alloys and their surfaces, and of interlayer exchange interactions in magnetic multilayers. The numer ical methods and algorithms employed in the calculations of this kind are discussed in detail, Stress is laid on the evaluation of their eff iciency and reliability.