Density-functional theory of the correlation energy in atoms and ions: A simple analytic model and a challenge

 

J. P. Perdew, E. R. McMullen, and Alex Zunger

Phys. Rev. A 23, 2785 – Published 1 June 1981

 

 

Abstract

A simple and accurate analytic model is derived for the correlation energy of any atom or ion within three densityfunctional approximations based on the uniform electron gas: the local-spin-density approximation (LSD), the selfinteraction corrected (SIC) version of LSD, and the antiparallel-spin LSD of Stoll et al. The last two approximations give good results for the correlation energies of neutral atoms, in contrast to LSD which overestimates these energies by a factor of 2. However, all three approximations show an incorrect $\ln Z$ leading behavior when the nuclear charge $Z$ tends to infinity at fixed electron number $N$. It is hard to see how any a priori electron-gas approximation can reproduce the exact leading behavior, which is constant or linear in $Z$ according to the value of $N$.

• Received 26 January 1981

DOI:https://doi.org/10.1103/PhysRevA.23.2785

©1981 American Physical Society

 https://sci-hub.se/https://journals.aps.org/pra/abstract/10.1103/PhysRevA.23.2785