Adiabatic connection at negative coupling strengths

Journal Article · Fri Jan 15 00:00:00 EST 2010 · Physical Review. A

DOI:https://doi.org/10.1103/PHYSREVA.81.012508· OSTI ID:21388721

Seidl, Michael ^[1]; Gori-Giorgi, Paola ^[2]

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1. Institute of Theoretical Physics, University of Regensburg, D-93040 Regensburg (Germany)
2. Laboratoire de Chimie Theorique, CNRS, Universite Pierre et Marie Curie, 4 Place Jussieu, F-75252 Paris (France)

The adiabatic connection of density functional theory (DFT) for electronic systems is generalized here to negative values of the coupling strength alpha (with attractive electrons). In the extreme limit alpha->-infinity 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 alpha->-infinity and the opposite limit of infinitely strong repulsion (alpha->+infinity) yields a rather accurate estimate of the second-order correlation energy E{sub c}{sup GL2}[rho] for several different densities rho, without using virtual orbitals. The same procedure is also applied to the Be isoelectronic series, analyzing the effects of near degeneracy.

• OSTI ID: 21388721
• Journal Information: Physical Review. A, Vol. 81, Issue 1; Other Information: DOI: 10.1103/PhysRevA.81.012508; (c) 2010 The American Physical Society; ISSN 1050-2947
• Country of Publication: United States
• Language: English

Related Subjects

74 ATOMIC AND MOLECULAR PHYSICS
75 CONDENSED MATTER PHYSICS
SUPERCONDUCTIVITY AND SUPERFLUIDITY
COUPLING
DENSITY FUNCTIONAL METHOD
ELECTRON CORRELATION
ELECTRONS
INTERPOLATION
CALCULATION METHODS
CORRELATIONS
ELEMENTARY PARTICLES
FERMIONS
LEPTONS
MATHEMATICAL SOLUTIONS
NUMERICAL SOLUTION
VARIATIONAL METHODS