A linear response approach to the calculation of the effective interaction parameters in the LDA+U method

TL;DR

This paper introduces a linear response method within the LDA+U framework to accurately compute effective interaction parameters, ensuring consistency and broad applicability across various correlated materials.

Contribution

It presents a simplified, rotational-invariant formulation of LDA+U and a new linear response approach for calculating Hubbard U that is internally consistent and implementation-independent.

Findings

Accurately computes structural and electronic properties of correlated materials.

Demonstrates robustness of the method across different systems.

Ensures minimal dependence on specific ab-initio implementation.

Abstract

In this work we reexamine the LDA+U method of Anisimov and coworkers in the framework of a plane-wave pseudopotential approach. A simplified rotational-invariant formulation is adopted. The calculation of the Hubbard U entering the expression of the functional is discussed and a linear response approach is proposed that is internally consistent with the chosen definition for the occupation matrix of the relevant localized orbitals. In this way we obtain a scheme whose functionality should not depend strongly on the particular implementation of the model in ab-initio calculations. We demonstrate the accuracy of the method, computing structural and electronic properties of a few systems including transition and rare-earth correlated metals, transition metal monoxides and iron-silicate.