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 ±0.03 eV.
@article{arxiv.1601.06767,
title = {Towards Fully Converged GW Calculations for Large Systems},
author = {Weiwei Gao and Weiyi Xia and Xiang Gao and Peihong Zhang},
journal= {arXiv preprint arXiv:1601.06767},
year = {2018}
}