title: Electronic Zero-Point Oscillations in the Strong-Interaction Limit of Density Functional Theory.
abstract: The exchange-correlation energy in Kohn-Sham density functional theory can be expressed exactly in terms of the change in the expectation of the electron-electron repulsion operator when, in the many-electron Hamiltonian, this same operator is multiplied by a real parameter λ varying between 0 (Kohn-Sham system) and 1 (physical system). In this process, usually called adiabatic connection, the one-electron density is kept fixed by a suitable local one-body potential. The strong-interaction limit of density functional theory, defined as the limit λ→∞, turns out to be like the opposite noninteracting Kohn-Sham limit (λ→0) mathematically simpler than the physical (λ = 1) case and can be used to build an approximate interpolation formula between λ→0 and λ→∞ for the exchange-correlation energy. Here we extend the systematic treatment of the λ→∞ limit [Phys. Rev. A 2007, 75, 042511] to the next leading term, describing zero-point oscillations of strictly correlated electrons, with numerical examples for small spherical atoms. We also propose an improved approximate functional for the zero-point term and a revised interpolation formula for the exchange-correlation energy satisfying more exact constraints.
authors.affiliation: Laboratoire de Chimie Théorique, CNRS, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris, France, Afdeling Theoretische Chemie, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands, Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, and Institute of Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany.
authors.forename: Paola
authors.initials: P
authors.lastname: Gori-Giorgi
authors.affiliation: Laboratoire de Chimie Théorique, CNRS, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris, France, Afdeling Theoretische Chemie, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands, Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, and Institute of Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany.
authors.forename: Giovanni
authors.initials: G
authors.lastname: Vignale
authors.affiliation: Laboratoire de Chimie Théorique, CNRS, Université Pierre et Marie Curie, 4 Place Jussieu, 75252 Paris, France, Afdeling Theoretische Chemie, Vrije Universiteit, De Boelelaan 1083, 1081 HV Amsterdam, The Netherlands, Department of Physics and Astronomy, University of Missouri, Columbia, Missouri 65211, and Institute of Theoretical Physics, University of Regensburg, 93040 Regensburg, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Seidl