DFT, L(S)DA, LDA+U, LDA+DMFT..., whether we do approach to a proper description of optical response for strongly correlated systems?

TL;DR

This paper critically reviews various ab initio DFT-based methods for accurately describing the electronic structure and optical properties of strongly correlated 3d oxides, highlighting their limitations and comparing them with traditional cluster models.

Contribution

It provides a comprehensive comparison of DFT, L(S)DA, LDA+U, and LDA+DMFT approaches for strongly correlated systems, emphasizing their strengths and weaknesses.

Findings

Standard LDA predicts NiO as a metal, contrary to its insulating nature.

Cluster models better capture crystal-field and charge transfer transitions.

DFT-based methods face challenges in accurately describing strongly correlated materials.

Abstract

I present a critical overview of so-called "{\it ab initio}" DFT (density fuctional theory) based calculation schemes for the description of the electronic structure, energy spectrum, and optical response for strongly correlated 3$d$ oxides, in particular, crystal-field and charge transfer transitions as compared with an "old"\, cluster model that does generalize crystal-field and ligand-field theory. As a most instructive illustration of validity of numerous calculation techniques I address the prototypical 3$d$ insulator NiO predicted to be a metal in frames of a standard LDA (local density approximation) band theory.