Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic Structures of MgB{$_2$} under Uniaxial and Hydrostatic
  Compression   Electronic and lattice properties of MgB{$_2$} under uniaxial and hydrostatic
compression are calculated. Lattice properties are optimized automatically by
using the first-principles molecular dynamics (FPMD) method. Features of the
electronic band structures under uniaxial and hydrostatic compression are quite
different each other.

12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
32
The categories of this paper are: atom-ph
30
The categories of this paper are: q-alg
34
The categories of this paper are: chem-ph
10
The categories of this paper are: q-bio
16
The categories of this paper are: stat
24
The categories of this paper are: dg-ga
9
The categories of this paper are: nlin
5
The categories of this paper are: gr-qc
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
22
The categories of this paper are: chao-dyn
25
The categories of this paper are: patt-sol
19
The categories of this paper are: eess
2
The categories of this paper are: math