Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Jahn-Teller-effect formation of the non-magnetic ground state for the d8
  system   It is shown that the d8 electron system occurring in the Ni2+ ion can have
the non-magnetic ground state in the atomic scale formed by the Jahn-Teller
effect. The tetragonal/trigonal off-cubic lattice distortion for the octahedral
site causes the splitting of the triplet 3A2g into a singlet-doublet structure
with the non-magnetic singlet lying lower provided the intra-atomic spin-orbit
coupling is taken into account.

17
The categories of this paper are: q-fin
32
The categories of this paper are: atom-ph
29
The categories of this paper are: funct-an
22
The categories of this paper are: chao-dyn
26
The categories of this paper are: bayes-an
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
30
The categories of this paper are: q-alg
36
The categories of this paper are: cmp-lg
7
The categories of this paper are: hep-th
10
The categories of this paper are: q-bio
35
The categories of this paper are: mtrl-th
6
The categories of this paper are: astro-ph
12
The categories of this paper are: nucl-th
8
The categories of this paper are: hep-ex