Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Hydration of Krypton and Consideration of Clathrate Models of
  Hydrophobic Effects from the Perspective of Quasi-Chemical Theory   AIMD results on a liquid krypton-water system are compared to recent XAFS
results for the radial hydration structure for a Kr atom in liquid water
solution. The comparisons with the liquid solution results are satisfactory and
significantly different from the radial distributions extracted from the data
on the solid clathrate hydrate phase. The calculations also produce the
coordination number distribution that can be examined for metastable
coordination structures suggesting possibilities for clathrate-like
organization; none are seen in these results. Clathrate pictures of hydrophobic
hydration are discussed, as is the quasi-chemical theory that should provide a
basis for clathrate pictures. Outer shell contributions are discussed and
accurately estimated; they are positive and larger than the positive
experimental hydration free energy of Kr(aq), implying that inner shell
contributions must be negative. Clathrate-like inner shell coordination
structures extracted from the simulation of the liquid, and then subjected to
quantum chemical optimization, always decomposed. Interactions with the outer
shell material are decisive in stabilizing coordination structures observed in
liquid solution and in clathrate phases. The ``what are we to tell students''
question about hydrophobic hydration, often answered with structural models
such as clathrate pictures, is then considered; we propose an alternative
answer that is consistent with successful molecular theories of hydrophobic
effects and based upon distinctive observable properties of liquid water.
Considerations of parsimony, for instance Ockham's razor, then suggest that
additional structural hypotheses in response to ``what are we to tell
students'' aren't required at this stage

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The categories of this paper are: mtrl-th
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-ex
2
The categories of this paper are: math
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The categories of this paper are: atom-ph
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The categories of this paper are: plasm-ph
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The categories of this paper are: comp-gas
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The categories of this paper are: nlin
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The categories of this paper are: econ
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The categories of this paper are: hep-th
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The categories of this paper are: chao-dyn
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The categories of this paper are: acc-phys
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The categories of this paper are: nucl-th
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The categories of this paper are: cmp-lg
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The categories of this paper are: dg-ga
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The categories of this paper are: q-fin