Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The L\"owdin orthogonalization and magnetoelectric coupling for
  noncentrosymmetric ions
16
The categories of this paper are: stat
25
The categories of this paper are: patt-sol
6
The categories of this paper are: astro-ph
20
The categories of this paper are: acc-phys
7
The categories of this paper are: hep-th
8
The categories of this paper are: hep-ex
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
14
The categories of this paper are: math-ph
1
The categories of this paper are: cs
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
9
The categories of this paper are: nlin
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg