Comparing $GW$+DMFT and LDA+DMFT for the testbed material SrVO$_3$

TL;DR

This paper compares the $GW$+DMFT and LDA+DMFT computational methods for SrVO$_3$, showing that both yield similar spectra that agree well with experiments, with $GW$+DMFT better capturing the lower Hubbard band.

Contribution

The study implements $GW$+DMFT in VASP and compares it with LDA+DMFT and experiments, highlighting the effects of different screening and bandwidth reductions.

Findings

Both methods produce similar spectra aligning with experimental data.

$GW$+DMFT more accurately reproduces the lower Hubbard side band.

Partial compensation of correlation effects explains the similarity in results.

Abstract

We have implemented the $GW$+dynamical mean field theory (DMFT) approach in the Vienna ab initio simulation package. Employing the interaction values obtained from the locally unscreened random phase approximation (RPA), we compare $GW$+DMFT and LDA+DMFT against each other and against experiment for SrVO$_3$. We observed a partial compensation of stronger electronic correlations due to the reduced $GW$ bandwidth and weaker correlations due to a larger screening of the RPA interaction, so that the obtained spectra are quite similar and well agree with experiment. Noteworthily, the $GW$+DMFT better reproduces the position of the lower Hubbard side band.