Doubly screened Coulomb correction approach for strongly correlated systems

TL;DR

The paper introduces a doubly screened Coulomb correction (DSCC) method for strongly correlated systems that improves accuracy over traditional DFT approaches while maintaining computational efficiency, effectively capturing Coulomb interactions in various materials.

Contribution

A novel DSCC approach that efficiently models on-site Coulomb interactions in strongly correlated materials, matching hybrid functional accuracy at lower computational cost.

Findings

DSCC achieves accuracy comparable to hybrid functionals.

DSCC is an order of magnitude faster than hybrid functionals.

DSCC can distinguish Coulomb interactions in metallic vs. insulating states.

Abstract

Strongly correlated systems containing d/f-electrons present a challenge to conventional density functional theory (DFT), such as the widely used local density approximation (LDA) or generalized gradient approximation (GGA). In this work, we developed a doubly screened Coulomb correction (DSCC) approach to perform on-site Coulomb interaction correction for strongly correlated materials. The on-site Coulomb interaction between localized d/f-electrons is determined from a model dielectric function that includes both the static dielectric and the Thomas-Fermi screening. All parameters of the dielectric model are efficiently obtained from self-consistent calculations. We applied DSCC to simulate the electronic and magnetic properties of typical 3d, 4f and 5f strongly correlated systems. The results show that the accuracy of DSCC is comparable to hybrid functionals, but an order of magnitude faster. In addition, DSCC can reflect the difference in the Coulomb interaction of the same element between metallic and insulating situations, similar to the popular but computationally expensive constrained random phase approximation (cRPA) approach. This feature suggests that DSCC is also a promising method for simulating Coulomb interaction parameters.