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 $3d$ (${\mathrm{SrTiO}}_{3}$, ${\mathrm{LaScO}}_{3}$, ${\mathrm{LaTiO}}_{3}$, ${\mathrm{LaVO}}_{3}$, ${\mathrm{LaCrO}}_{3}$, ${\mathrm{LaMnO}}_{3}$, ${\mathrm{LaFeO}}_{3}$, and ${\mathrm{SrMnO}}_{3}$), $4d$ (${\mathrm{SrZrO}}_{3}$, ${\mathrm{SrTcO}}_{3}$, and ${\mathrm{Ca}}_{2}{\mathrm{RuO}}_{4}$) and $5d$ (${\mathrm{SrHfO}}_{3}$, ${\mathrm{KTaO}}_{3}$, and ${\mathrm{NaOsO}}_{3}$) 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.