Unconstrained Variational Determination of the Kohn-Sham Potential

TL;DR

This paper introduces an unconstrained variational approach to determine the Kohn-Sham potential in Density Functional Theory, revealing its physical meaning as an optimal non-interacting system without fixing the electron density.

Contribution

It presents a novel unconstrained variational scheme for deriving the Kohn-Sham potential, clarifying its physical interpretation as an optimal non-interacting system.

Findings

The Kohn-Sham potential can be obtained through an unconstrained variational principle.

The approach does not require fixing the electron density.

It provides insight into the physical meaning of the Kohn-Sham system.

Abstract

Density Functional Theory's Kohn-Sham (KS) potential emerges as the minimizing effective potential in an unconstrained variational scheme that does not involve fixing the unknown single-electron density. The physical content behind the virtual KS system, that of a non-interacting electronic system representing optimally the interacting one, is brought to light.