# Interplay of charge-transfer and Mott-Hubbard physics approached by an efficient combination of self-interaction correction and dynamical mean-field theory

## TL;DR

This paper enhances the DFT+DMFT method by incorporating self-interaction correction for oxygen, improving the description of charge-transfer and Mott-Hubbard physics in transition-metal oxides like NiO.

## Contribution

It introduces an efficient SIC implementation into DFT+DMFT, explicitly including oxygen correlations and improving intersite $p-d$ correlation treatment.

## Key findings

- Spectral features of NiO are well described with local DMFT self-energies.
- In-gap states in Li$_x$Ni$_{1-x}$O are confirmed theoretically.
- The method effectively captures charge-transfer and Mott-Hubbard physics interplay.

## Abstract

Late transition-metal oxides with small charge-transfer energy $\Delta$ raise issues for state-of-the-art correlated electronic structure schemes such as the combination of density functional theory (DFT) with dynamical mean-field theory (DMFT). The accentuated role of the oxygen valence orbitals in these compounds asks for an enhanced description of ligand-based correlations. Utilizing the rocksalt-like NiO as an example, we present an advancement of charge self-consistent DFT+DMFT by including self-interaction correction (SIC) applied to oxygen. This introduces explicit onsite O correlations as well as an improved treatment of intersite $p-d$ correlations. Due to the efficient SIC incorporation in a pseudopotential form, the DFT+sicDMFT framework is an advanced but still versatile method to address the interplay of charge-transfer and Mott-Hubbard physics. We revisit the spectral features of stoichiometric NiO and reveal the qualitative sufficiency of local DMFT self-energies in describing spectral peak structures usually associated with explicit nonlocal processes. For Li$_x$Ni$_{1-x}$O, prominent in-gap states are verified by the present theoretical study.