Optimally-Tuned Starting Points for One-Shot GW Calculations of Solids*

Accurate quasiparticle (QP) band gaps can be obtained via ab initio many-body perturbation theory within the GW approximation, where G is the one-electron Green's function and W is the screened Coulomb interaction. In practice, one-shot G0W0 calculations which do not self-consistently update G or W are often carried out to reduce computational expense and complexity. However, G0W0 calculations exhibit a strong starting-point dependence on the eigensystem used to construct G and W, limiting the predictive power of this approach. Here, we present G0W0 calculations performed using a Wannier-localized, optimally tuned screened range-separated hybrid (WOT-SRSH) starting point. This functional is optimally tuned per system to obey the ionization potential theorem and has been shown to produce band gaps for semiconductors and insulators in excellent agreement with experiment [1]. We show that G0W0@WOT-SRSH leads to QP band gaps and band structures comparable in accuracy to those produced by self-consistent GW schemes for a range of insulators and semiconductors at a reduced cost. We also discuss the sensitivity of G0W0@WOT-SRSH to perturbations in the underlying parameters in the SRSH functional about their optimal values, as well as the implications for optical gaps and spectra.