Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Dangling bonds in a-Si:H revisited: A combined Multifrequency EPR and
  DFT Study
32
The categories of this paper are: atom-ph
3
The categories of this paper are: physics
14
The categories of this paper are: math-ph
7
The categories of this paper are: hep-th
6
The categories of this paper are: astro-ph
0
The categories of this paper are: hep-ph
11
The categories of this paper are: hep-lat
22
The categories of this paper are: chao-dyn
2
The categories of this paper are: math
15
The categories of this paper are: nucl-ex
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
10
The categories of this paper are: q-bio