Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Inverse melting in lattice-gas models   Inverse melting is the phenomenon, observed in both Helium isotopes, by which
a crystal melts when cooled at constant pressure. I investigate discrete-space
analogs of inverse melting by means of two instances of a
triangular-lattice-gas system endowed with a soft-core repulsion and a
short-ranged attraction. To reconstruct the phase diagram, I use both
transfer-matrix and Monte Carlo methods, as well as low-temperature series
expansions. In one case, a phase behavior reminiscent of Helium emerges, with a
loose-packed phase (which is solid-like for low temperatures and liquid-like
for high temperatures) extending down to zero temperature for low pressures and
the possibility of melting the close-packed solid by isobaric cooling. At
variance with previous model studies of inverse melting, the driving mechanism
of the present phenomenon is mainly geometrical, related to the larger
free-energy cost of a ``vacancy'' in the loose-packed solid than in the
close-packed one.

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The categories of this paper are: chem-ph
11
The categories of this paper are: hep-lat
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
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The categories of this paper are: hep-th
5
The categories of this paper are: gr-qc
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The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
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The categories of this paper are: stat
2
The categories of this paper are: math
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The categories of this paper are: q-fin
18
The categories of this paper are: econ
8
The categories of this paper are: hep-ex
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The categories of this paper are: plasm-ph
1
The categories of this paper are: cs
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The categories of this paper are: atom-ph