An accurate exchange energy functional in excited-state density functional theory

TL;DR

This paper introduces a new exchange energy functional tailored for excited states within density functional theory, significantly improving the accuracy of excitation energy calculations.

Contribution

It presents an excited-state exchange energy functional that accounts for state dependence, extending the local-density approximation to excited states.

Findings

Achieves highly accurate excitation energies

Extends ground-state LDA to excited states

Demonstrates improved functional performance

Abstract

An exchange energy functional is proposed and tested for obtaining a class of excited-state energies using density-functional formalism. The functional is the excited-state counterpart of the local-density approximation functional for the ground-state. It takes care of the state-dependence of the energy functional and leads to highly accurate excitation energies.