Orbital spaces and densityfunctional theory
Abstract
Only part of the correlation energy can be obtained from the wave function when expanded as a finite and linear combination of Slater determinants. For the remaining part, it was proposed by several authors to use densityfunctional theory. Thus, various methods coupling wave functions with density functionals were investigated in the past. In the present a class of such methods was developed, relying on a partition of the orbital space. Notably, for this coupled method special efforts were made to avoid double countings between the contributions of the wave function and the density functional. Moreover, the coupling was defined in order to allow a systematic improvement of the results. As a second step, the method was put to the test for spherically symmetric systems, especially in the case of near degeneracy. The numerical results obtained were discussed in order to improve the model. Finally, the wave function contribution that was retained relied on a coupledcluster formalism restricted to a small orbital space, whereas the density functional was chosen as a semilocal expression based on the physical picture of oneparticle ionization potentials.
 Authors:
 Laboratoire Interuniversitaire des Systemes Atmospheriques, CNRS UMR 7583 et Universites Paris 7 et Paris 12, 94010 Creteil (France)
 Laboratoire de Chimie Theorique, CNRS UMR 7616 et Universite Pierre et Marie Curie, 75252 Paris (France)
 Publication Date:
 OSTI Identifier:
 20982316
 Resource Type:
 Journal Article
 Resource Relation:
 Journal Name: Physical Review. A; Journal Volume: 75; Journal Issue: 3; Other Information: DOI: 10.1103/PhysRevA.75.032519; (c) 2007 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
 Country of Publication:
 United States
 Language:
 English
 Subject:
 74 ATOMIC AND MOLECULAR PHYSICS; ARGON; ATOMS; BERYLLIUM; COUPLING; DENSITY; DENSITY FUNCTIONAL METHOD; ELECTRON CORRELATION; HELIUM; IONIZATION POTENTIAL; MAGNESIUM; NEON; PARTITION; SLATER METHOD; WAVE FUNCTIONS
Citation Formats
Gutle, C., and Savin, A. Orbital spaces and densityfunctional theory. United States: N. p., 2007.
Web. doi:10.1103/PHYSREVA.75.032519.
Gutle, C., & Savin, A. Orbital spaces and densityfunctional theory. United States. doi:10.1103/PHYSREVA.75.032519.
Gutle, C., and Savin, A. Thu .
"Orbital spaces and densityfunctional theory". United States.
doi:10.1103/PHYSREVA.75.032519.
@article{osti_20982316,
title = {Orbital spaces and densityfunctional theory},
author = {Gutle, C. and Savin, A.},
abstractNote = {Only part of the correlation energy can be obtained from the wave function when expanded as a finite and linear combination of Slater determinants. For the remaining part, it was proposed by several authors to use densityfunctional theory. Thus, various methods coupling wave functions with density functionals were investigated in the past. In the present a class of such methods was developed, relying on a partition of the orbital space. Notably, for this coupled method special efforts were made to avoid double countings between the contributions of the wave function and the density functional. Moreover, the coupling was defined in order to allow a systematic improvement of the results. As a second step, the method was put to the test for spherically symmetric systems, especially in the case of near degeneracy. The numerical results obtained were discussed in order to improve the model. Finally, the wave function contribution that was retained relied on a coupledcluster formalism restricted to a small orbital space, whereas the density functional was chosen as a semilocal expression based on the physical picture of oneparticle ionization potentials.},
doi = {10.1103/PHYSREVA.75.032519},
journal = {Physical Review. A},
number = 3,
volume = 75,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}

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