The ground-state energy, electron density, and related properties of ordinary matter can be computed efficiently when the exchange-correlation energy as a functional of the density is approximated semilocally. We propose the first meta-GGA (meta-generalized gradient approximation) that is fully constrained, obeying all 17 known exact constraints that a meta-GGA can. It is also exact or nearly exact for a set of appropriate norms, including rare-gas atoms and nonbonded interactions. This SCAN (strongly constrained and appropriately normed) meta-GGA achieves remarkable accuracy for systems where the exact exchange-correlation hole is localized near its electron, and especially for lattice constants and weak interactions.
@article{arxiv.1504.03028,
title = {Strongly Constrained and Appropriately Normed Semilocal Density Functional},
author = {Jianwei Sun and Adrienn Ruzsinszky and John P. Perdew},
journal= {arXiv preprint arXiv:1504.03028},
year = {2015}
}