Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Electronic Properties of TiO$_2$ Nanotubes   quasi-one-dimensional (1D) titania nanostructures - single-walled nanotubes
formed by rolling [101] planes of TiO$_2$ (anatase phase) are modeled and their
electronic properties and bond orders indices are studied using the
tight-binding band theory. We show that all zigzag (n,0)- and armchair
(n,n)-like nanotubes are uniformly semiconducting, and the band gap trends to
vanish as the tube diameters decrease. It was established that the zigzag (n,0)
nanotubes configurations are more likely to form when the diameters are larger
1 nm. The Ti-O covalent bonds were found to be the strongest interactions in
TiO$_2$ tubes, whereas Ti-Ti bonds proved to be much weaker.

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The categories of this paper are: chem-ph
5
The categories of this paper are: gr-qc
8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
37
The categories of this paper are: supr-con
28
The categories of this paper are: alg-geom
6
The categories of this paper are: astro-ph
2
The categories of this paper are: math
23
The categories of this paper are: solv-int
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The categories of this paper are: q-alg
0
The categories of this paper are: hep-ph
19
The categories of this paper are: eess
13
The categories of this paper are: quant-ph
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The categories of this paper are: comp-gas
14
The categories of this paper are: math-ph
22
The categories of this paper are: chao-dyn