Adiabatic connection at negative coupling strengths

M. Seidl, P. Gori Giorgi

Research output: Contribution to JournalArticle

Abstract

The adiabatic connection of density functional theory (DFT) for electronic systems is generalized here to negative values of the coupling strength α (with attractive electrons). In the extreme limit α→-∞ a simple physical solution is presented and its implications for DFT (as well as its limitations) are discussed. For two-electron systems (a case in which the present solution can be calculated exactly), we find that an interpolation between the limit α→-∞ and the opposite limit of infinitely strong repulsion (α→+∞) yields a rather accurate estimate of the second-order correlation energy EcGL2[ρ] for several different densities ρ, without using virtual orbitals. The same procedure is also applied to the Be isoelectronic series, analyzing the effects of near degeneracy. © 2010 The American Physical Society.
Original languageEnglish
Article number012508
Pages (from-to)012508
Number of pages9
JournalPhysical Review A
Volume81
DOIs
Publication statusPublished - 2010

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