English

Convexity and translational invariance constraint on the exchange-correlation functional

Condensed Matter 2009-10-28 v1

Abstract

Knowledge of the properties of the exchange-correlation functional in the form 1λvxc([ρλ],rλ)\frac 1\lambda v_{xc}([\rho _\lambda ],\frac{{\bf r}}\lambda ), where ρλ(r)=\rho _\lambda ({\bf r})= λ3ρ(λr),\lambda ^3\rho (\lambda {\bf r}), is important when expressing the exchange-correlation energy as a line integral % E_{xc}[\rho ]=\int_0^1d\lambda \int d{\bf r}\frac 1\lambda v_{xc}([\rho _\lambda ],\frac{{\bf r}}\lambda )\left[ 3\rho ({\bf r})+{\bf r.\nabla }\rho ({\bf r})\right] (van Leeuwen and Baerends, Phys. Rev. A {\bf 51}, 170 (1995)). With this in mind, it is shown that in the low density limit % \lim_{\lambda \rightarrow 0}\int \rho ({\bf r})\nabla ^2\frac 1\lambda v_{xc}([\rho _\lambda ],\frac{{\bf r}}\lambda )\ d^3r\leq 4\pi \int \rho (% {\bf r})^2d^3r. This inequality is violated in the local-density approximation.

Keywords

Cite

@article{arxiv.cond-mat/9602069,
  title  = {Convexity and translational invariance constraint on the exchange-correlation functional},
  author = {Daniel Joubert and Mel Levy},
  journal= {arXiv preprint arXiv:cond-mat/9602069},
  year   = {2009}
}

Comments

5 pages, REVTeX, to appear in Phys. Rev. A

R2 v1 2026-07-22T11:52:09.498Z