Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Mixed Heisenberg Chains. I. The Ground State Problem   We consider a mechanism for competing interactions in alternating Heisenberg
spin chains due to the formation of local spin-singlet pairs. The competition
of spin-1 and spin-0 states reveals hidden Ising symmetry of such alternating
chains.

33
The categories of this paper are: plasm-ph
5
The categories of this paper are: gr-qc
31
The categories of this paper are: ao-sci
3
The categories of this paper are: physics
34
The categories of this paper are: chem-ph
2
The categories of this paper are: math
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
1
The categories of this paper are: cs
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
17
The categories of this paper are: q-fin
27
The categories of this paper are: comp-gas
35
The categories of this paper are: mtrl-th
9
The categories of this paper are: nlin
29
The categories of this paper are: funct-an