✦ LIBER ✦
Correlation energy contributions from low-lying states to density functionals based on an electron gas with a gap
✍ Scribed by Claudine Gutle; Andreas Savin; Joseph B. Krieger; Jiqiang Chen
- Publisher
- John Wiley and Sons
- Year
- 1999
- Tongue
- English
- Weight
- 117 KB
- Volume
- 75
- Category
- Article
- ISSN
- 0020-7608
No coin nor oath required. For personal study only.
✦ Synopsis
Orbitals having negative orbital energies in density functional theory define a space for generating correlated wave functions and contributions to the correlation energies. The most important contribution from such states comes from the valence orbitals, while the Rydberg orbitals make a much smaller contribution. This provides a significant correction to the correlation energy obtained from a functional based on the uniform electron gas with a gap when there is a near degeneracy between the ground state and a two-particle excited state.