1,315 research outputs found
Leading-order behavior of the correlation energy in the uniform electron gas
We show that, in the high-density limit, restricted M{\o}ller-Plesset (RMP)
perturbation theory yields for the correlation energy per electron in the uniform electron gas,
where is the Seitz radius. This contradicts an earlier derivation which
yielded . The reason for the
discrepancy is explained.Comment: 4 pages, accepted for publication in Int. J. Quantum Che
Exact energy of the spin-polarized two-dimensional electron gas at high density
We derive the exact expansion, to , of the energy of the high-density
spin-polarized two-dimensional uniform electron gas, where is the Seitz
radius.Comment: 7 pages, 1 figure and 1 table, submitted to Phys. Rev.
The uniform electron gas
The uniform electron gas or UEG (also known as jellium) is one of the most
fundamental models in condensed-matter physics and the cornerstone of the most
popular approximation --- the local-density approximation --- within
density-functional theory. In this article, we provide a detailed review on the
energetics of the UEG at high, intermediate and low densities, and in one, two
and three dimensions. We also report the best quantum Monte Carlo and
symmetry-broken Hartree-Fock calculations available in the literature for the
UEG and discuss the phase diagrams of jellium.Comment: 37 pages, 8 figures, 8 tables, accepted for publication in WIRES
Computational Molecular Scienc
Correlation energy of two electrons in a ball
We study the ground-state correlation energy of two electrons of
opposite spin confined within a -dimensional ball () of radius .
In the high-density regime, we report accurate results for the exact and
restricted Hartree-Fock energy, using a Hylleraas-type expansion for the former
and a simple polynomial basis set for the latter. By investigating the exact
limiting correlation energy E_{\rm c}^{(0)} = \lim_{R \to 0} \Ec for various
values of , we test our recent conjecture [J. Chem. Phys. {\bf 131} (2009)
241101] that, in the large- limit, for
any spherically-symmetric confining external potential, where .Comment: 6 pages, 2 figure
Advanced Information Technology Application in ERP Systems
Current Enterprise Resource Planning Systems (ERP) are used to track companies’ finances, human resources, and logistics. Upcoming market-driven requirements focus on outside connectivity and up-to-date information supply, including business-to-business support, e-commerce, and virtual enterprises. How can these requirements be met by applying emerging information technologies? This paper focuses on future development of ERP systems emphasizing on technical aspects of information technology application as enabler. It briefly discusses existing research approaches and potential research and development issues
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