Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Magnetostructural Effect in the Multiferroic BiFeO3-BiMnO3 Checkerboard
  from First Principles
3
The categories of this paper are: physics
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
11
The categories of this paper are: hep-lat
13
The categories of this paper are: quant-ph
18
The categories of this paper are: econ
2
The categories of this paper are: math
9
The categories of this paper are: nlin
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
12
The categories of this paper are: nucl-th
30
The categories of this paper are: q-alg
31
The categories of this paper are: ao-sci