Linearized Jastrow-style fluctuations on spin-projected Hartree-Fock

Journal Article · Sat Dec 21 04:00:00 EST 2013 · Journal of Chemical Physics

DOI:https://doi.org/10.1063/1.4848075· OSTI ID:22253701

Henderson, Thomas M.; Scuseria, Gustavo E. ^[1]

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1. Department of Chemistry and Department of Physics and Astronomy, Rice University, Houston, Texas 77251-1892 (United States)

The accurate and efficient description of strong electronic correlations remains an important objective in electronic structure theory. Projected Hartree-Fock theory, where symmetries of the Hamiltonian are deliberately broken and projectively restored, all with a mean-field computational scaling, shows considerable promise in this regard. However, the method is neither size extensive nor size consistent; in other words, the correlation energy per particle beyond broken-symmetry mean field vanishes in the thermodynamic limit, and the dissociation limit of a molecule is not the sum of the fragment energies. These two problems are closely related. Recently, Neuscamman [Phys. Rev. Lett. 109, 203001 (2012)] has proposed a method to cure the lack of size consistency in the context of the antisymmetrized geminal power wave function (equivalent to number-projected Hartree-Fock-Bogoliubov) by using a Jastrow-type correlator in Hilbert space. Here, we apply the basic idea in the context of projected Hartree-Fock theory, linearizing the correlator for computational simplicity but extending it to include spin fluctuations. Results are presented for the Hubbard Hamiltonian and for some simple molecular systems.

• OSTI ID: 22253701
• Journal Information: Journal of Chemical Physics, Journal Name: Journal of Chemical Physics Journal Issue: 23 Vol. 139; ISSN JCPSA6; ISSN 0021-9606
• Country of Publication: United States
• Language: English

Related Subjects

71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
73 NUCLEAR PHYSICS AND RADIATION PHYSICS
DISSOCIATION
ELECTRONIC STRUCTURE
FLUCTUATIONS
HAMILTONIANS
HARTREE-FOCK METHOD
HARTREE-FOCK-BOGOLYUBOV THEORY
HILBERT SPACE
MEAN-FIELD THEORY
WAVE FUNCTIONS