Uniform electron gas from the Colle-Salvetti functional: Missing long-range correlations
Abstract
Colle and Salvetti [Theor. Chim. Acta 37, 329 (1975)] approximated the correlation energy of a many-electron system as a functional of the Hartree-Fock one-particle density matrix. The most fundamental and least approximate version of this functional [their Eq. (9)] is found to yield only 25% of the true correlation energy of a uniform electron gas, and not 100% as previously believed. While short-range correlations are described surprisingly well by this approach, important long-range correlations are missing. Such correlations are energetically negligible in atoms, but cannot be ignored in more extended systems, including solids as well as molecules.
- Publication:
-
Physical Review A
- Pub Date:
- March 2001
- DOI:
- 10.1103/PhysRevA.63.032513
- Bibcode:
- 2001PhRvA..63c2513T
- Keywords:
-
- 31.15.Ew;
- 71.10.Ca;
- 71.15.-m;
- 31.25.Eb;
- Density-functional theory;
- Electron gas Fermi gas;
- Methods of electronic structure calculations;
- Electron correlation calculations for atoms and ions: ground state