Eur. Phys. J. B (2018) 91: 189
https://doi.org/10.1140/epjb/e2018-90111-0

Regular Article

On-top density in the nonlinear metallic screening and its implication on the exchange-correlation energy functional^★

Institute for Solid State Physics, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba 277-8581, Japan

^a e-mail: takada@issp.u-tokyo.ac.jp

Received: 1 March 2018
Received in final form: 8 June 2018
Published online: 29 August 2018

Abstract

In comparison with the accurate data on the on-top electron density n(0) in the proton-embedded electron gas with the density parameter r_s in the range 1−12 obtained by diffusion Monte Carlo (DMC) simulations, we have successfully constructed an alternative form of the exchange-correlation energy functional in the density functional theory by imposing the constraint due to the cusp theorem on the well-known Perdew–Burke–Ernzerhof (PBE) functional. Although PBE does not, our functional, referred to as the cusp-corrected PBE (ccPBE), reproduces the DMC data on n(0) in the entire range of r_s.