Generalized gradient approximation for solids and their surfaces

TL;DR

The paper introduces PBEsol, a revised GGA functional that restores the gradient expansion for exchange energy, leading to improved predictions of equilibrium properties for densely-packed solids and their surfaces.

Contribution

It presents PBEsol, a new GGA functional that corrects the bias of previous GGAs by restoring the gradient expansion, enhancing accuracy for solid-state properties.

Findings

PBEsol improves equilibrium properties of densely-packed solids.

It provides better surface energy predictions.

The functional aligns well with first-principles gradient expansion.

Abstract

Successful modern generalized gradient approximations (GGA) are biased toward atomic energies. Restoration of the first-principles gradient expansion for the exchange energy over a wide range of density gradients eliminates this bias. We introduce PBEsol, a revised Perdew-Burke-Ernzerhof GGA that improves equilibrium properties for many densely-packed solids and their surfaces.