Green/WeakCoupling: Implementation of fully self-consistent finite-temperature many-body perturbation theory for molecules and solids

TL;DR

This paper introduces the Green/WeakCoupling module, a software implementation for fully self-consistent finite-temperature many-body perturbation theory, enabling accurate simulations of molecules and solids.

Contribution

It presents the implementation of self-consistent GW and GF2 methods within an open-source package, with practical tools and tutorials for materials simulation.

Findings

Enables finite-temperature self-consistent perturbation calculations

Provides tools for analyzing and post-processing simulations

Supports real materials with diagrammatic perturbation theory

Abstract

The accurate ab initio simulation of molecules and periodic solids with diagrammatic perturbation theory is an important task in quantum chemistry, condensed matter physics, and materials science. In this article, we present the WeakCoupling module of the open-source software package Green, which implements fully self-consistent diagrammatic weak coupling simulations, capable of dealing with real materials in the finite-temperature formalism. The code is licensed under the permissive MIT license. We provide self-consistent GW (scGW) and self-consistent second-order Green's function perturbation theory (GF2) solvers, analysis tools, and post-processing methods. This paper summarizes the theoretical methods implemented and provides background, tutorials and practical instructions for running simulations.