Towards Fully Converged GW Calculations for Large Systems

TL;DR

This paper introduces a new method that significantly accelerates fully converged GW calculations for large systems, enabling accurate quasiparticle energy predictions with much reduced computational effort.

Contribution

A simple and effective method is developed to drastically speed up GW calculations for large systems, maintaining high accuracy.

Findings

Achieved nearly 100x speed-up for 256-atom MgO supercells

Maintained small numerical error of ±0.03 eV

Demonstrated effectiveness on large-scale systems

Abstract

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.