Electronic and optical properties of cadmium fluoride: The role of many-body effects

CAPPELLINI, GIANCARLO;Furthmouller J;CADELANO, EMILIANO;Bechstedt F.

2013-01-01

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Abstract

Electronic excitations and optical spectra of CdF2 are calculated up to ultraviolet employing state-of-the-art techniques based on density functional theory and many-body perturbation theory. The GW scheme proposed by Hedin has been used for the electronic self-energy to calculate single-particle excitation properties as energy bands and densities of states. For optical propertiesmany-body effects, treated within the Bethe-Salpeter equation framework, turn out to be crucial. A bound exciton located about 1 eV below the quasiparticle gap is predicted. Within the present scheme the optical absorption spectra and other optical functions show an excellent agreement with experimental data. Moreover, we tested different schemes to obtain the best agreement with experimental data. Among the several schemes, we suggest a self-consistent quasiparticle energy scheme.