Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: The DFT+$\Sigma_2$ method for electron correlation effects at transition
  metal surfaces
36
The categories of this paper are: cmp-lg
22
The categories of this paper are: chao-dyn
31
The categories of this paper are: ao-sci
11
The categories of this paper are: hep-lat
34
The categories of this paper are: chem-ph
29
The categories of this paper are: funct-an
24
The categories of this paper are: dg-ga
5
The categories of this paper are: gr-qc
37
The categories of this paper are: supr-con
14
The categories of this paper are: math-ph
3
The categories of this paper are: physics
16
The categories of this paper are: stat
19
The categories of this paper are: eess
33
The categories of this paper are: plasm-ph
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ