Sum-rules of the response potential in the strongly-interacting limit of DFT

TL;DR

This paper investigates the response component of the exchange-correlation potential in density functional theory, revealing a simple sum rule in the strongly-interacting limit for one-dimensional systems, which could impact calculations of electronic properties.

Contribution

It introduces a new sum rule for the response potential in the infinite interaction limit of DFT, specifically for one-dimensional cases.

Findings

Response potential satisfies a simple sum rule in 1D at strong interaction limit.

The sum rule provides insights into the behavior of the exchange-correlation potential.

Potential applications in improving band gap and excitation energy calculations.

Abstract

The response part of the exchange-correlation potential of Kohn-Sham density functional theory plays a very important role, for example for the calculation of accurate band gaps and excitation energies. Here we analyze this part of the potential in the limit of infinite interaction in density functional theory, showing that in the one-dimensional case it satisfies a very simple sum rule.