Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Superstructure, sodium ordering and antiferromagnetism in NaxCoO2
  (0.75<x<1.0)
19
The categories of this paper are: eess
0
The categories of this paper are: hep-ph
28
The categories of this paper are: alg-geom
20
The categories of this paper are: acc-phys
10
The categories of this paper are: q-bio
18
The categories of this paper are: econ
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
11
The categories of this paper are: hep-lat
25
The categories of this paper are: patt-sol
21
The categories of this paper are: adap-org
16
The categories of this paper are: stat
36
The categories of this paper are: cmp-lg