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# Simple model for the spherically- and system-averaged pair density: Results for two-electron atoms

Physical Review A (Impact Factor: 3.04). 11/2004; DOI:10.1103/PhysRevA.71.032513
Source: arXiv

ABSTRACT As shown by Overhauser and others, accurate pair densities for the uniform electron gas may be found by solving a two-electron scattering problem with an effective screened electron-electron repulsion. In this work we explore the extension of this approach to nonuniform systems, and we discuss its potential for density functional theory. For the spherically- and system-averaged pair density of two-electron atoms we obtain very accurate short-range properties, including, for nuclear charge $Z\ge 2$, on-top'' values (zero electron-electron distance) essentially indistinguishable from those coming from precise variational wavefunctions. By means of a nonlinear adiabatic connection that separates long- and short-range effects, we also obtain Kohn-Sham correlation energies whose error is less than 4 mHartree, again for $Z\ge 2$, and short-range-only correlation energies whose accuracy is one order of magnitude better. Comment: 9 pages, 6 figures (14 .eps files); revised version, to appear in Phys. Rev. A

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##### Article: The electron-gas pair density and its geminal description
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ABSTRACT: Attempts to generalize the density functional theory are summarized. A possible pair density functional theory is linked to the Overhauser parametrization of the electron- gas pair density. The importance of the cumulant partitioning is stressed and a modied Overhauser approach for the cumulant 2-body reduced density matrix, the contraction of which determines the 1-body reduced density matrix, is discussed.

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