Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On pair functions for strong correlations   The UHF wave function may be written as a spin-contaminated \textit{pair}
wave function of the APSG form, and the overlap of the alpha and beta
corresponding orbitals of the UHF solution can be taken as a proxy for the
strength of the correlation captured by breaking symmetry. We demonstrate this
with calculations on one- and two-dimensional hydrogen clusters and make
contact with the well studied Hubbard model. The UHF corresponding orbitals
pair in a manner that allows a smooth evolution from doubly occupied orbitals
at small distance to one in which wave function breaks symmetry, segregating
the $\alpha$ and $\beta$ electrons onto distinct sublattices at large
distances. By performing spin projection on these UHF solutions, we address
strong correlations that are difficult to capture at intermediate distances
using a single determinant. Approved for public release: LA-UR-13-22691.

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The categories of this paper are: stat
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The categories of this paper are: bayes-an
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The categories of this paper are: math-ph
33
The categories of this paper are: plasm-ph
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The categories of this paper are: atom-ph
5
The categories of this paper are: gr-qc
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The categories of this paper are: alg-geom
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The categories of this paper are: mtrl-th
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The categories of this paper are: nlin
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The categories of this paper are: q-alg
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The categories of this paper are: chem-ph
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The categories of this paper are: hep-ex
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The categories of this paper are: astro-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: funct-an
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The categories of this paper are: q-bio