Ab Initio Energy Band Methods

摘要: The beginning of this work was in 1964, when I a graduate student. At that point, any detailed experimental data relating to the band structure alkali-halide crystals lacking. only generally accepted results for these materials identification shoulder optical absorption substances on high energy side exciton as being due transition at r, center Brillouin Zone. These transitions were identified using usual BSW notation from p-like valence (Г15) an s-like conduction (Г1) [1]. There appeared, time, attempt by Phillips identify virtually every spectra feature terms excitons critical points and van Hove singularities [2]. attempts shortly shown be error [3 ,4 ,5].