Electron-hole excitations and optical spectra of bulk SrO from many-body perturbation theory

This paper reports the quasiparticle band structure and the optical absorption spectrum of SrO, using many-body perturbation theory. The quasiparticle band structure is calculated within the GW approximation. Taking the electron-hole interaction into consideration, electron-hole pair states and optical excitations are obtained by solving the Bethe-Salpeter equation for the electron-hole two-particle Green function. The calculated band gap for SrO is 6.0 eV, which is in good agreement with the corresponding experimental results. The theoretical result of optical absorption spectrum for SrO is also in close agreement with the experimental data. In particular, the calculated excitation energy for the lowest exciton peak in the optical absorption spectra of SrO reproduces very well the corresponding experimental result.