Quasiparticle band structures and optical spectra of β-cristobalite SiO2 -: art. no. 085102

Band structures and dielectric functions are calculated using density-functional theory and local-density approximation for three beta-cristobalite modifications of SiO2 with space-group symmetries Fd3m, I (4) over bar 2d, and P2(1)3. Quasiparticle corrections for the Kohn-Sham eigenvalues are determined in a GW approach. The fundamental energy gaps, absorption onsets, and dielectric functions are discussed and compared in the light of experimental data and previous calculations.