A van der Waals density functional for solids

TL;DR

This paper investigates and refines a non-local correlation functional to improve the accuracy of van der Waals interaction descriptions in solids, achieving better interlayer binding energies and geometries.

Contribution

It introduces two new versions of the VV10 functional tailored for solids, enhancing the modeling of van der Waals interactions in layered and close-packed materials.

Findings

Refitted functional yields highly accurate interlayer binding energies.

VV10 functional accurately predicts equilibrium geometries.

New functionals improve van der Waals interaction modeling in solids.

Abstract

The recent non-local correlation functional of Vydrov and van Voorhis[J. Chem. Phys. 133, 244103 (2010)] is investigated and two new versions of the functional are suggested as being appropriate for describing van der Waals interactions in solids. A refitting of the original functional is demonstrated to result in very accurate interlayer binding energies for weakly bonded layered solids. A VV10 functional based on the generalized gradient approximation by Armiento and Mattsson[Phys. Rev. B 72, 085108 (2005)], while performing slightly worse for interlayer binding is highly successful in describing the equilibrium geometries of both weakly bonded and close packed solids.