Quasi-non-local gradient-level exchange-correlation approximation for metals and alloys

TL;DR

This paper introduces a quasi-non-local gradient-level exchange-correlation approximation tailored for metals and alloys, addressing the limitations of universal GGA functionals by optimizing element-specific parameters.

Contribution

It proposes a novel quasi-non-local approximation based on element-specific optimization, improving accuracy for transition metals and their alloys.

Findings

Universal gradient approximations are inconsistent across metals.

Element-specific optimization enhances accuracy for transition metals.

The scheme performs well on various transition metal alloys.

Abstract

The flexibility of common generalized gradient approximation for the exchange-correlation energy is investigated by monitoring the equilibrium volume of transition metals. It is shown that no universal gradient-level approximation yielding consistent errors for all metals exists. Based on an element-specific optimization, the concept of quasi-non-local gradient-level approximation is introduced. The strength of the scheme is demonstrated on several transition metal alloys.