Yukawa potential for realistic prediction of Hubbard and Hund interaction parameters for transition metals

TL;DR

This paper introduces a Yukawa potential-based method to accurately predict Hubbard and Hund interaction parameters for transition metals, improving the modeling of strongly correlated materials.

Contribution

It develops a Yukawa screening approach to refine Hubbard and Hund parameters for transition metals, enhancing the predictive power of the generalized Hubbard model.

Findings

Yukawa screening constant $\

$U$ and $J$ values are more realistic for transition metals.

Modified Racah parameters improve the accuracy of interaction predictions.

Abstract

The generalized Hubbard model is an important theoretical model for modeling strongly correlated materials. To be able to theoretically predict the properties of the materials, the model requires Hubbard's $U$ and Hund's $J$ parameter that represent the on-site Coulomb and exchange interaction, respectively. For bare Coulomb interactions, the analytic expression of $U$ and $J$ are analytically described by Racah's $A,B,C$ parameters. However, the values of $U$ are too large for transition-metal-based materials. To obtain more accurate values for realistic materials, we employ a Yukawa-type screened Coulomb interaction, characterized by screening constant $\lambda$. We characterize $\lambda$ for transition metals. The modified $A,B,C$ parameters give a more realistic $U$ and $J$ values.