Basic notions and applications of the augmented spherical wave method

The basic ideas of modern band theory and the functionality of state of the art calculational schemes are illustrated with the augmented spherical wave (ASW) method. Our description includes a short review of the underlying theory as well as a derivation of the most important formulas. We explain some steps toward the computational implementation and discuss aspects of practical application. Finally, the capabilities offered by the ASW method are demonstrated by an investigation of the electronic structure of FeS2, which belongs to the increasingly exciting class of pyrite-type transition metal dichalcogenides.