Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Multilayered crystals of macroions under slit-confinement   The crystalline ground state of macroions confined between two neutral
parallel plates in the presence of their homogeneously spread counterions is
calculated by lattice-sum minimization of candidate phases involving up to six
layers. For increasing macroion density, a cascade of solid-solid transitions
is found involving various multilayered crystals. The cascade includes
triangular monolayer and buckled bilayer as well as rhombic, squared and
triangular phase structures.

8
The categories of this paper are: hep-ex
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The categories of this paper are: patt-sol
2
The categories of this paper are: math
19
The categories of this paper are: eess
10
The categories of this paper are: q-bio
30
The categories of this paper are: q-alg
15
The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
0
The categories of this paper are: hep-ph
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: stat
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The categories of this paper are: quant-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: adap-org