Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Real-space grid representation of momentum and kinetic energy operators
  for electronic structure calculations
0
The categories of this paper are: hep-ph
8
The categories of this paper are: hep-ex
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
24
The categories of this paper are: dg-ga
20
The categories of this paper are: acc-phys
23
The categories of this paper are: solv-int
34
The categories of this paper are: chem-ph
15
The categories of this paper are: nucl-ex
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
14
The categories of this paper are: math-ph
26
The categories of this paper are: bayes-an
16
The categories of this paper are: stat
29
The categories of this paper are: funct-an
19
The categories of this paper are: eess