Large scale GW calculations

TL;DR

This paper introduces an efficient, scalable GW calculation method for large molecules and solids that avoids explicit virtual state evaluation and dielectric matrix inversion, enabling studies of systems with thousands of electrons.

Contribution

The authors develop a parallel GW calculation technique using contour deformation that is applicable to large-scale systems starting from DFT calculations.

Findings

Successfully applied to water/semiconductor interfaces with thousands of electrons

Achieved efficient frequency integration without explicit virtual state evaluation

Demonstrated scalability for large molecular and solid systems

Abstract

We present GW calculations of molecules, ordered and disordered solids and interfaces, which employ an efficient contour deformation technique for frequency integration, and do not require the explicit evaluation of virtual electronic states, nor the inversion of dielectric matrices. We also present a parallel implementation of the algorithm which takes advantage of separable expressions of both the single particle Green's function and the screened Coulomb interaction. The method can be used starting from density functional theory calculations performed with semi-local or hybrid functionals. We applied the newly developed technique to GW calculations of systems of unprecedented size, including water/semiconductor interfaces with thousands of electrons.