Density Functionals that Recognize Covalent, Metallic, and Weak Bonds

TL;DR

This paper introduces a new semilocal meta-GGA functional that better describes covalent, metallic, and weak bonds in molecules, surfaces, and solids by recognizing different orbital overlaps, improving upon traditional LSDA and GGA methods.

Contribution

A novel semilocal meta-GGA functional that accurately captures all bond types by utilizing an appropriate dimensionless ingredient to recognize orbital overlaps.

Findings

Improved description of weak interactions without sacrificing accuracy for strong bonds.

Effective application to molecules, surfaces, and solids.

Enhanced recognition of orbital overlaps across bond types.

Abstract

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.