Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: First-principles equation of state and phase stability for the Ni-Al
  system under high pressures
7
The categories of this paper are: hep-th
34
The categories of this paper are: chem-ph
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
11
The categories of this paper are: hep-lat
17
The categories of this paper are: q-fin
35
The categories of this paper are: mtrl-th
33
The categories of this paper are: plasm-ph
36
The categories of this paper are: cmp-lg
12
The categories of this paper are: nucl-th
15
The categories of this paper are: nucl-ex
8
The categories of this paper are: hep-ex
2
The categories of this paper are: math
16
The categories of this paper are: stat
18
The categories of this paper are: econ