Semilocal Meta-GGA Exchange-Correlation Approximation From Adiabatic Connection Formalism: Extent and Limitations

TL;DR

This paper extends the adiabatic connection semilocal correlation (ACSC) approach to the meta-GGA level, constructing a new correlation functional based on high and low-density limits, with insights into its advantages and limitations.

Contribution

It introduces a meta-GGA level ACSC correlation functional, specifically based on the TPSS functional, highlighting its properties and potential for density functional theory improvements.

Findings

TPSS-ACSC is one-electron self-interaction free

It is accurate for strictly correlated regimes

It demonstrates advantages and disadvantages of ACSC functionals

Abstract

The incorporation of a strong interaction regime within the approximate, semilocal exchange-correlation functionals still remains a very challenging task for density functional theory. One of the promising attempts in this direction is the recently proposed adiabatic connection semilocal correlation (ACSC) approach [Phys. Rev. B 2019, 99, 085117] allowing to construct the correlation energy functionals by interpolation of the high and low-density limits for the given semi-local approximation. The current study extends the ACSC method to the meta-GGA level of theory, providing some new insights. As an example, we construct the correlation energy functional base on the high and low-density limits of the Tao-Perdew-Starverov-Scuseria (TPSS) functional. Arose in this way TPSS-ACSC functional is one electron self-interaction free, accurate for the strictly correlated, and quasi-two-dimensional regimes. Based on simple examples, we show the advantages and disadvantages of ACSC semi-local functionals and provide some new guidelines for future developments in this context.