Rigorous description of exchange-correlation energy of many-electron systems

TL;DR

This paper presents a rigorous formulation of the exchange-correlation energy in many-electron systems using eigenfunctional theory, proposing a method that surpasses the local density approximation in density functional theory.

Contribution

It introduces a rigorous expression for ground state energy and a novel method beyond the local density approximation in density functional theory.

Findings

Derived a rigorous ground state energy expression

Proposed an effective method beyond local density approximation

Enhanced accuracy in modeling electron correlation

Abstract

With the eigenfunctional theory, we study a general interacting electron system, and give a rigorous expression of its ground state energy which is composed of two parts, one part is contributed by the non-interacting electrons, and another one is represented by the correlation functions that are controlled by the electron correlation. Moreover, according to the rigorous expression of the ground state energy, an effective method beyond the local density approximation of the density functional theory is proposed.