Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Structural properties and Raman spectra of columbite-type
  NiNb$_{2-x}$V$_x$O$_6$ synthesized under high pressure
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
24
The categories of this paper are: dg-ga
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
30
The categories of this paper are: q-alg
2
The categories of this paper are: math
19
The categories of this paper are: eess
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
18
The categories of this paper are: econ
32
The categories of this paper are: atom-ph
36
The categories of this paper are: cmp-lg