Instruct: Identify the main and secondary category of Arxiv papers based on the titles
Query: Quantum-chemical studies of rutile nanoparticles toxicity I. Defect-free
  rod-like model clusters
26
The categories of this paper are: bayes-an
14
The categories of this paper are: math-ph
5
The categories of this paper are: gr-qc
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
18
The categories of this paper are: econ
16
The categories of this paper are: stat
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
35
The categories of this paper are: mtrl-th
7
The categories of this paper are: hep-th
15
The categories of this paper are: nucl-ex
21
The categories of this paper are: adap-org