Linearized self-consistent quasiparticle GW method: Application to semiconductors and simple metals

TL;DR

This paper introduces a linearized self-consistent quasiparticle GW method implementation using the LAPW basis, improving efficiency and applicability to semiconductors and metals, with results closely matching previous data.

Contribution

The paper presents a novel linearization of the self-energy in the scQPGW method, enabling efficient calculations using Matsubara frequencies and the LAPW basis without pseudopotentials.

Findings

Results closely match previous scQPGW data for semiconductors and metals.

The method exhibits N^3 scaling with system size, suitable for larger systems.

The implementation facilitates future many-body diagrammatic resummations like GW+DMFT.

Abstract

We present a code implementing the linearized self-consistent quasiparticle GW method (scQPGW) in the LAPW basis. Our approach is based on the linearization of the self-energy around zero frequency which differs it from the existing implementations of the scQPGW method. The linearization allows us to use Matsubara frequencies instead of real ones. As a result it gives us an advantage in terms of efficiency, allowing us easily switch to the imaginary time representation the same way as in the space time method. The all electron LAPW basis set eliminates the need for pseudopotentials. We discuss the advantages of our approach, such as its N^3 scaling with the system size, as well as its shortcomings. We apply our approach to study electronic properties of selected semiconductors, insulators, and simple metals and show that our code produces results very close to the previously published scQPGW data. Our implementation is a good platform for further many body diagrammatic resummations such as GW+DMFT.