  We study the thermal quantum correlations and entanglement in spin-1
Bose-Hubbard model with two and three particles. While we use negativity to
calculate entanglement, more general non-classical correlations are quantified
using a new measure based on a necessary and sufficient condition for
zero-discord state. We demonstrate that the energy level crossings in the
ground state of the system are signalled by both the behavior of thermal
quantum correlations and entanglement.
