Role of electronic correlations in Ga

TL;DR

This paper develops an extended AMF functional with onsite Coulomb interaction to better account for electronic correlations in gallium, improving predictions of its structural parameters and phase behavior.

Contribution

The paper introduces an extended AMF functional combined with a specific Coulomb interaction to accurately model electronic correlations in gallium.

Findings

Reduces deviations in Ga positional parameters by about 20%.

Aligns symmetry lowering with the Ga phase diagram.

Demonstrates the importance of electronic correlations in Ga modeling.

Abstract

An extended around mean field (AMF) functional for less localized $p$ electrons is developed to quantify the influence of electronic correlations in $\alpha$-Ga. Both the local density approximation (LDA) and generalized gradient approximation (GGA) are known to mispredict the Ga positional parameters. The extended AMF functional together with an onsite Coulomb interaction of $U_{\rm eff}=1.1$ eV, as obtained from constraint LDA calculations, reduces the deviations by about 20%. The symmetry lowering coming along with the electronic correlations turns out to be in line with the Ga phase diagram.