Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Prediction of polar ordered oxynitride perovskites   Using a materials by design approach, the authors find a class of ordered
oxynitride piezoelectrics with perovskite structure. They predict that ordered
YSiO2N and YGeO2N are characterized by large nonlinear optic responses and by
some of the largest polarizations known to date.

28
The categories of this paper are: alg-geom
17
The categories of this paper are: q-fin
36
The categories of this paper are: cmp-lg
3
The categories of this paper are: physics
0
The categories of this paper are: hep-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
26
The categories of this paper are: bayes-an
19
The categories of this paper are: eess
6
The categories of this paper are: astro-ph
14
The categories of this paper are: math-ph
37
The categories of this paper are: supr-con
12
The categories of this paper are: nucl-th
11
The categories of this paper are: hep-lat
33
The categories of this paper are: plasm-ph
1
The categories of this paper are: cs