Gutzwiller Density Functional Theory: a formal derivation and application to ferromagnetic nickel

TL;DR

This paper derives the Gutzwiller Density Functional Theory, applies it to ferromagnetic nickel, and demonstrates improvements over standard DFT, highlighting issues with double-counting corrections in correlated-electron methods.

Contribution

It provides a comprehensive derivation of Gutzwiller DFT applicable to various symmetries and demonstrates its effectiveness in modeling ferromagnetic nickel.

Findings

Improved ground state property calculations for nickel.

Better quasi-particle band structure predictions.

Identifies challenges with double-counting corrections.

Abstract

We present a detailed derivation of the Gutzwiller Density Functional Theory that covers all conceivable cases of symmetries and Gutzwiller wave functions. The method is used in a study of ferromagnetic nickel where we calculate ground state properties (lattice constant, bulk modulus, spin magnetic moment) and the quasi-particle band structure. Our method resolves most shortcomings of an ordinary Density Functional calculation on nickel. However, the quality of the results strongly depends on the particular choice of the double-counting correction. This constitutes a serious problem for all methods that attempt to merge Density Functional Theory with correlated-electron approaches based on Hubbard-type local interactions.