Article

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

Physical Review A (Impact Factor: 2.81). 11/2004; 71(3). DOI: 10.1103/PhysRevA.71.032513

Source: arXiv

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Paola Gori-Giorgi, Aug 26, 2013 Available from: Data provided are for informational purposes only. Although carefully collected, accuracy cannot be guaranteed. The impact factor represents a rough estimation of the journal's impact factor and does not reflect the actual current impact factor. Publisher conditions are provided by RoMEO. Differing provisions from the publisher's actual policy or licence agreement may be applicable.

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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. - [Show abstract] [Hide abstract]

**ABSTRACT:**We present an extensive comparative study of ground-state densities and pair distribution functions for electrons confined in two-dimensional parabolic quantum dots over a broad range of coupling strength and electron number. We first use spin-density-functional theory to determine spin densities that are compared with Diffusion Monte Carlo (DMC) data. This accurate knowledge of one-body properties is then used to construct and test a local approximation for the electron-pair correlations. We find very satisfactory agreement between this local scheme and the available DMC data, and provide a detailed picture of two-body correlations in a coupling-strength regime preceding the formation of Wigner-like electron ordering.Physical review. B, Condensed matter 02/2005; 72(4). DOI:10.1103/PhysRevB.72.045306 · 3.66 Impact Factor - [Show abstract] [Hide abstract]

**ABSTRACT:**The exchange and correlation $E_{xc}$ of strongly correlated electrons in 2D layers of finite width are studied as a function of the density parameter $r_s$, spin-polarization $\zeta$ and the temperature $T$. We explicitly treat strong-correlation effects via pair-distribution functions, and introduce an equivalent constant-density approximation (CDA) applicable to all the inhomogeneous densities encountered here. The width $w$ defined via the CDA provides a length scale defining the $z$-extension of the quasi-2D layer resident in the $x$-$y$ plane. The correlation energy $E_c$ of the quasi-2D system is presented as an interpolation between a 1D gas of electron-rods (for $w/r_s>1$) coupled via a log(r) interaction, and a 3D Coulomb fluid closely approximated from the known {\it three-dimensional} correlation energy when $w/r_s$ is small. Results for the $E_{xc}(r_s,\zeta,T)$, the transition to a spin-polarized phase, the effective mass $m^*$, the Land\'e $g$-factor etc., are reported here. Comment: Revtex manuscript, 9 postscript figuresPhysical review. B, Condensed matter 06/2005; 72(12). DOI:10.1103/PhysRevB.72.125339 · 3.66 Impact Factor