Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Structural, Elastic, Electronic, and Optical Properties of Layered TiNX
  (X = F, Cl, Br, I) Compounds: a Density Functional Theory Study
8
The categories of this paper are: hep-ex
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
21
The categories of this paper are: adap-org
19
The categories of this paper are: eess
26
The categories of this paper are: bayes-an
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
36
The categories of this paper are: cmp-lg
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
1
The categories of this paper are: cs
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
13
The categories of this paper are: quant-ph
23
The categories of this paper are: solv-int