Self-interaction correction in the LDA+U method

TL;DR

This paper identifies a shortcoming in the LDA+U method related to self-interaction correction and proposes a new scheme that improves the accuracy of electronic property predictions for Gd metal.

Contribution

The paper derives a new expression for the double-counting energy, leading to an improved LDA+U scheme with better experimental agreement.

Findings

Enhanced electronic property predictions for Gd metal

More consistent results with experiments compared to previous schemes

Revised self-interaction correction improves LDA+U accuracy

Abstract

We present one inherent shortcoming of the LDA+U method in respect of its self-interaction correction of the LDA. By reexamining the mean-field approximation on the Hubbard energy in the Hartree-Fock form, we have derived a new expression for the ``double-counting'' energy which led to a more reasonable self-interaction correction in an alternative LDA+U scheme. For the bulk Gd metal, the new scheme resulted in electronic properties more consistent with experiments in comparison to the LDA and the existing LDA+U schemes.