Density Functional Application to Strongly Correlated Electron Systems

TL;DR

This paper reanalyzes the LSDA+U density functional approach, derives sum rules for on-site interactions, and applies the method to cuprate structures to elucidate their electronic properties.

Contribution

It provides a detailed derivation of sum rules, implementation into a solver, and application to cuprates, enhancing understanding of strongly correlated electron systems.

Findings

Sum rules linking U and J to on-site interactions

Implementation of LSDA+U in FPLO solver

Insights into electronic structure of cuprates

Abstract

The LSDA+U approach to density functional theory is carefully reanalyzed. Its possible link to single-particle Green's function theory is occasionally discussed. A simple and elegant derivation of the important sum rules for the on-site interaction matrix elements linking them to the values of U and J is presented. All necessary expressions for an implementation of LSDA+U into a non-orthogonal basis solver for the Kohn-Sham equations are given, and implementation into the FPLO solver is made. Results of application to several planar cuprate structures are reported in detail and conclusions on the interpretation of the physics of the electronic structure of the cuprates are drawn.