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.
@article{arxiv.1209.3038,
title = {A van der Waals density functional for solids},
author = {Torbjörn Björkman},
journal= {arXiv preprint arXiv:1209.3038},
year = {2012}
}