Computationally-efficient semilocal approximations of density functional theory at the level of the local spin density approximation (LSDA) or generalized gradient approximation (GGA) poorly describe weak interactions. We show improved descriptions for weak bonds (without loss of accuracy for strong ones) from a newly-developed semilocal meta-GGA (MGGA), by applying it to molecules, surfaces, and solids. We argue that this improvement comes from using the right MGGA dimensionless ingredient to recognize all types of orbital overlap.
@article{arxiv.1303.5688,
title = {Density Functionals that Recognize Covalent, Metallic, and Weak Bonds},
author = {Jianwei Sun and Bing Xiao and Yuan Fang and Robin Haunschild and Pan Hao and Adrienn Ruzsinszky and Gabor I. Csonka and Gustavo E. Scuseria and John P. Perdew},
journal= {arXiv preprint arXiv:1303.5688},
year = {2015}
}