Self-interaction correction in a simple model

TL;DR

This paper explores methods to improve self-interaction corrections in Density Functional Theory using a simple particle model, providing insights into the balance between orthonormality and energy variance.

Contribution

It introduces a simplified model to analyze self-interaction corrections in DFT, offering a clearer understanding of the underlying trade-offs.

Findings

Different SIC approaches are compared within the model.

The balance between orthonormality and energy variance is elucidated.

Benchmark results from Hartree-Fock calculations are used for validation.

Abstract

We discuss various ways to handle self-interaction corrections (SIC) to Density Functional Theory (DFT) calculations. To that end, we use a simple model of few particles in a finite number of states together with a simple zero-range interaction for which full Hartree-Fock can easily be computed as a benchmark. The model allows to shed some light on the balance between orthonormality of the involved states and energy variance.