Electronic energy bands and optical transitions in tetragonal germanium dioxide

Abstract

The electronic energy band structure of the tetragonal crystallographic modification of germanium dioxide (GeO 2) has been calculated by the APW method. Application of selection rules indicate only two allowed direct transitions at the center of the Brillouin zone which correlate with observed room temperature optical properties at the fundamental absorption edge in single crystals. The calculated band structure also predicts an indirect transition which, although not inconsistent with the optical data, cannot be completely verified without additional and more refined experimental work.