ABSTRACT
The Korringa-Kohn-Rostocker or the KKR multiple scattering technique is one of the most sophisticated and accurate methods for the first-principles, parameterfree calculation of the energy band structure of solids. Theoretical understanding of ordered systems received a boost with the enunciation of Bloch’s Theorem and a whole edifice of elegant theories was built around it. With disorder, the basic assumption of lattice periodicity on which Bloch’s Theorem rests, is no longer valid. New ideas and new approaches are called for.
