Various Approaches to Obtain the Minimal Complexes of Bands and Their Manifestation in Spectra of Strongly Anisotropic Crystals

In semiconductor physics the examination of the band structure is a very important problem. There are many numerical methods for calculation of the spectra, however the determination of their symmetry is sometimes problematic. The symmetry description of a spectrum is important because on the basis of it we can obtain e.g. the selection rules for optical transitions...