Study of a Nonlocal Density scheme for electronic--structure calculations

TL;DR

This paper explores a nonlocal density functional based on the exchange-correlation kernel for electronic structure calculations, showing slight improvements in lattice constants and gaps but limited impact on cohesive energies.

Contribution

It introduces a nonlocal density scheme using the exchange-correlation kernel, extending beyond the local density approximation for better electronic structure predictions.

Findings

Small improvement in lattice constants and gaps

Limited correction to cohesive energies

Overestimation of cohesive energy remains

Abstract

An exchange-correlation energy functional beyond the local density approximation, based on the exchange-correlation kernel of the homogeneous electron gas and originally introduced by Kohn and Sham, is considered for electronic structure calculations of semiconductors and atoms. Calculations are carried out for diamond, silicon, silicon carbide and gallium arsenide. The lattice constants and gaps show a small improvement with respect to the LDA results. However, the corresponding corrections to the total energy of the isolated atoms are not large enough to yield a substantial improvement for the cohesive energy of solids, which remains hence overestimated as in the LDA.