Optimally-Tuned Range-Separated Hybrid Functional Starting Points for One-Shot GW Calculations*

Accurate quasiparticle energies and subsequently fundamental band gaps can be obtained using ab initio many-body perturbation theory (MBPT) within the GW approximation. Frequently, so-called one-shot G0W0 calculations are carried out to reduce computational expense and complexity. However, one-shot G0W0 can be sensitive to the Kohn-Sham eigensystem that is used as a starting point for constructing the Green’s function and RPA screened Coulomb interaction, limiting the predictive power of this approach. Here, we present a one-shot G0W0 approach that uses a Wannier-localized, optimally-tuned screened range-separated hybrid (WOT-SRSH) functional as a starting point. The WOT-SRSH functional is tuned for each system to satisfy an approximate extension of the IP theorem, a procedure which has recently been shown to predict excellent band gaps. In this work, we perform G0W0@WOT-SRSH for several bulk semiconductors and insulators and find that it can significantly reduce starting point dependence. We compare our calculations with experiment and discuss the potential predictive power of this approach for one-shot G0W0.