Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Laser Ablation Production of Platinum Nitride and its Possible
  Structure   The synthesis of platinum nitride by the laser ablation method is reported.
The spectroscopic results show that nitrogen is in interstitial sites of
platinum as N-units, contradicting the accepted configuration for PtN2 where it
is as N2-units. To elucidate this point we did density functional calculations
to correlate composition with nitrogen sites. For dilute nitrogen
concentrations, x < 0.2, nitrogen would be in six-fold coordinated sites
(octahedral interstices) as N-units. For 0.2 < x < 1.5, nitrogen would be in
tetrahedral interstices as N-units. Only for x > 1.5 the N2-configuration in
octahedral sites is attained.

37
The categories of this paper are: supr-con
31
The categories of this paper are: ao-sci
22
The categories of this paper are: chao-dyn
17
The categories of this paper are: q-fin
9
The categories of this paper are: nlin
20
The categories of this paper are: acc-phys
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
16
The categories of this paper are: stat
33
The categories of this paper are: plasm-ph
3
The categories of this paper are: physics
27
The categories of this paper are: comp-gas
5
The categories of this paper are: gr-qc
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
1
The categories of this paper are: cs