Intracule densities in the strong-interaction limit of density functional theory

The correlation energy in density functional theory can be expressed exactly in terms of the change in the probability of finding two electrons at a given distance r(12) (intracule density) when the electron-electron interaction is multiplied by a real parameter lambda varying between 0 (Kohn-Sham system) and 1 (physical system). In this process, usually called adiabatic connection, the one-electron density is (ideally) kept fixed by a suitable local one-body potential. While an accurate intracule density of the physical system can only be obtained from expensive wavefunction-based calculations, being able to construct good models starting from Kohn-Sham ingredients would highly improve the accuracy of density functional calculations. To this purpose, we investigate the intracule density in the lambda --> infinity limit of the adiabatic connection. This strong-interaction limit of density functional theory turns out to be, like the opposite non-interacting Kohn-Sham limit, mathematically simple and can be entirely constructed from the knowledge of the one-electron density. We develop here the theoretical framework and, using accurate correlated one-electron densities, we calculate the intracule densities in the strong interaction limit for few atoms. Comparison of our results with the corresponding Kohn-Sham and physical quantities provides useful hints for building approximate intracule densities along the adiabatic connection of density functional theory.     

An application of correlation energy density functionals to atoms and molecules

Four density functionals — including that recently introduced by Perdew ((1986) Phys Rev B33: 8822)—are tested for first-row atoms, hydrides and dimers. Calculated contributions of the correlation energy to the ionization potentials and electron affinities of atoms and to the dissociation energies of molecules are compared with empirical values which were reevaluated for this purpose. An improvement over Hartree-Fock is found in all cases if the self-interaction or the gradient correction are included in the density functional, although there is a rather large variation in the accuracy of the predictions.     

The Effect of Layers Interaction on the Stiffness of Bending Deformations of Multilayered Carbon Nanoribbons

Physics of the Solid State - The effect of a weak nonbonded layers interaction on the bending resistance of a multilayered graphene nanoribbon is studied. A numerical simulation of bending of a...     

Double-Lattice Magnetoplasmonic Structures Based on BIG and Perforated Gold Films

Physics of the Solid State - A method of manufacturing double-lattice magnetoplasmonic crystals with the structure (Au/BIG)2, in which the plasmon gold lattices are displaced relative to each other...     

Magnetopause charging and transfer of momentum and energy into magnetosphere

The theory of charged current sheets is compared with plasma data of Prognoz-8, Interball-1, Polar, and Cluster satellites. The possibility of momentum and energy transfer into the magnetosphere, irrespective of magnetic field line reconnection, as a specific dynamo effect, is shown. This relates statistical properties of the turbulent boundary layers with the character of the transfer through thin boundaries.     

Statistics of resonance width shifts as a signature of eigenfunction nonorthogonality

We consider an open (scattering) quantum system under the action of a perturbation of its closed counterpart. It is demonstrated that the resulting shift of resonance widths is a sensitive indicator of the nonorthogonality of resonance wave functions, being zero only if those were orthogonal. Focusing further on chaotic systems, we employ random matrix theory to introduce a new type of parametric statistics in open systems and derive the distribution of the resonance width shifts in the regime of weak coupling to the continuum.