Exchange-Correlation Hole in Polarized Insulators: Implications for the Microscopic Functional Theory of Dielectrics

TL;DR

This paper proves that in polarized insulators, the exchange-correlation hole and energy depend on both the density and macroscopic polarization, not just the bulk density, impacting the microscopic functional theory of dielectrics.

Contribution

It provides a direct proof that the exchange-correlation hole in polarized insulators depends on polarization, not solely on bulk density, refining the understanding of dielectric functionals.

Findings

Exchange-correlation hole depends on density and polarization.

Exchange-correlation energy is not determined by density alone.

Implications for microscopic functional theory of dielectrics.

Abstract

We present a simple and direct proof that the exchange-correlation hole, and therefore the exchange-correlation energy, in a polarized insulator is not determined by the bulk density alone. It is uniquely characterized by the density and the macroscopic electric polarization of the dielectric medium.