Abstract
The density-gradient expansion of the fermion exchange hole is analyzed in real space. Unlike the local-density approximation, the second-order gradient-expansion approximation is found to violate two important properties of the exact hole: The exact hole is negative everywhere, and represents a deficit of one electron. Imposition of these exact constraints leads to an accurate new density functional for the exchange energy. Residual errors in the exchange energy for atoms are about 1% of this quantity. The new functional approximation may be generalized to include correlation.
Keywords
PhysicsCutoffSpace (punctuation)Energy (signal processing)FermionLocal-density approximationEnergy functionalDensity gradientDensity functional theoryStatistical physicsQuantum electrodynamicsQuantum mechanicsComputer science
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Publication Info
- Year
- 1985
- Type
- article
- Volume
- 55
- Issue
- 16
- Pages
- 1665-1668
- Citations
- 477
- Access
- Closed
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Cite This
John P. Perdew
(1985).
Accurate Density Functional for the Energy: Real-Space Cutoff of the Gradient Expansion for the Exchange Hole.
Physical Review Letters
, 55
(16)
, 1665-1668.
https://doi.org/10.1103/physrevlett.55.1665
Identifiers
- DOI
- 10.1103/physrevlett.55.1665