Work

Construction of a semilocal exchange density functional from a three-dimensional electron gas collapsing to two dimensions

Year: 2023

Type: article

Abstract: In a recent paper [Horowitz et al., Phys. Rev. B 107, 195120 (2023)], an alternative route has been proposed to construct the so-called exchange-correlation (xc) enhancement factor ${F}_{xc}$ of density-functional theory, defined as the enhancement of a realistic xc energy density over its local exchange-only counterpart. This new route, based on the ab initio calculation of the exact exchange energy density of a family of electron-density profiles, was implemented on the basis of jellium-slab exact-exchange self-consistent calculations. Here, we follow this route to construct a meta-generalized-gradient approximation (MGGA) for exchange from a nonuniform one-dimensional coordinate scaling, which we implement on the basis of a number of calculations performed for model densities of electrons confined by infinite-barrier walls, as the electron system is shrunk from three to two dimensions. Our MGGA yields exchange energies that approach in the two-dimensional (2D) limit the exact exchange energy of a 2D electron gas, by appealing to a scaling of the MGGA exchange enhancement factor.

Source: Physical review. B./Physical review. B

DOI: 10.1103/physrevb.108.115119

Authors: C. M. Horowitz, C. R. Proetto, J. M. Pitarke