Same-spin dynamical correlation effects on the electron localization

TL;DR

This paper investigates how same-spin dynamical electron correlations influence electron localization, proposing a simple modification to the Electron Localization Function (ELF) to account for these effects.

Contribution

It introduces a computationally affordable modification of ELF to incorporate same-spin dynamical correlation effects in electron localization analysis.

Findings

The modified ELF better captures electron localization in weakly correlated systems.

Same-spin dynamical correlations significantly affect electron localization measures.

The approach provides a practical way to include dynamical correlations in electronic structure analysis.

Abstract

The Electron Localization Function (ELF) -- as proposed originally by Becke and Edgecombe -- has been widely adopted as a descriptor of atomic shells and covalent bonds. The ELF takes into account the antisymmetry of Fermions but it neglects the multi-reference character of a truly interacting many-electron state. Electron-electron interactions induce, schematically, different kind of correlations: non-dynamical correlations mostly affect stretched molecules and strongly correlated systems; dynamical correlations dominate in weakly correlated systems. Here, within an affordable computational effort, we estimate the effects of same-spin dynamical correlations on the electron localization by means of a simple modification of the ELF.