Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On how good DFT exchange-correlation functionals are for H bonds in
  small water clusters: Benchmarks approaching the complete basis set limit   The ability of several density-functional theory (DFT) exchange-correlation
functionals to describe hydrogen bonds in small water clusters (dimer to
pentamer) in their global minimum energy structures is evaluated with reference
to second order Moeller Plesset perturbation theory (MP2). Errors from basis
set incompleteness have been minimized in both the MP2 reference data and the
DFT calculations, thus enabling a consistent systematic evaluation of the true
performance of the tested functionals. Among all the functionals considered,
the hybrid X3LYP and PBE0 functionals offer the best performance and among the
non-hybrid GGA functionals mPWLYP and PBE1W perform the best. The popular BLYP
and B3LYP functionals consistently underbind and PBE and PW91 display rather
variable performance with cluster size.

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The categories of this paper are: plasm-ph
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The categories of this paper are: eess
12
The categories of this paper are: nucl-th
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The categories of this paper are: chem-ph
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The categories of this paper are: econ
10
The categories of this paper are: q-bio
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: q-fin
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The categories of this paper are: stat
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The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
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The categories of this paper are: mtrl-th
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The categories of this paper are: adap-org
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The categories of this paper are: ao-sci
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The categories of this paper are: q-alg