Towards Fully Converged GW Calculations for Large Systems
  Although the GW approximation is recognized as one of the most accurate theories for predicting materials excited states properties, scaling up conventional GW calculations for large systems remains a major challenge. We present a powerful and simple-to-implement method that can drastically accelerate fully converged GW calculations for large systems. We demonstrate the performance of this new method by calculating the quasiparticle band gap of MgO supercells. A speed-up factor of nearly two orders of magnitude is achieved for a system contaning 256 atoms (1024 velence electrons) with a negligibly small numerical error of $\pm 0.03$ eV. 
Weiwei Gao, Weiyi Xia, Xiang Gao, Peihong Zhang
physics.comp-ph cond-mat.mtrl-sci