Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the Contact Numbers of Ball Packings on Various Hexagonal Grids   We describe the structure of the different hexagonal grids in dimension d=3,
propose short notation for them, investigate the contact numbers of ball
packings in these grids and share some computational results up to 200 balls,
using mainly the greedy algorithm. We consider the octahedral grid, too.

28
The categories of this paper are: alg-geom
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
1
The categories of this paper are: cs
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
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The categories of this paper are: solv-int
4
The categories of this paper are: cond-mat
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The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
16
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: mtrl-th
36
The categories of this paper are: cmp-lg