Optical and excitonic properties of transition metal oxide perovskites by the Bethe-Salpeter equation

We present a systematic investigation of the role and importance of excitonic effects on the optical properties of transitions metal oxide perovskites. A representative set of 14 compounds has been selected, including 3d (SrTiO3, LaScO3, LaTiO3, LaVO3, LaCrO3, LaMnO3, LaFeO3, and SrMnO3), 4d (SrZrO3, SrTcO3, and Ca2RuO4) and 5d (SrHfO3, KTaO3, and NaOsO3) perovskites, covering a band gap ranging from 0.1 eV to 6.1 eV and exhibiting different electronic, structural, and magnetic properties. Optical conductivities and optical transitions including electron-hole interactions are calculated through the solution of the Bethe-Salpeter equation (BSE) with quasiparticle energies evaluated by the single-shot G(0)W(0) approximation. The exciton binding energies are computed by means of a model BSE, carefully benchmarked against the full-BSE method, in order to obtain well-converged results in terms of k-point sampling. The predicted results are compared with available measured data, with an overall satisfactory agreement between theory and experiment.