Response function analysis of excited-state kinetic energy functional constructed by splitting k-space

TL;DR

This paper introduces a new approach for constructing excited-state energy functionals in density functional theory by splitting k-space, and analyzes its response function to demonstrate its effectiveness.

Contribution

The paper presents a novel method for building excited-state energy functionals through k-space splitting and provides a response function analysis to justify its advantages.

Findings

The kinetic energy functional obtained via k-space splitting shows high accuracy.

Response function analysis explains why k-space splitting is effective for excited states.

The method offers a promising route for developing excited-state density functionals.

Abstract

Over the past decade, fundamentals of time independent density functional theory for excited state have been established. However, construction of the corresponding energy functionals for excited states remains a challenging problem. We have developed a method for constructing functionals for excited states by splitting k-space according to the occupation of orbitals. In this paper we first show the accuracy of kinetic energy functional thus obtained. We then perform a response function analysis of the kinetic energy functional proposed by us and show why method of splitting the k-space could be the method of choice for construction of energy functionals for excited states.