need to sum over thermally excited inter-level transitions. The problem of calculating the neutron cross section then reduces to deriving the single ion response for 1. Given that each Ni II ion is in a S = 1 state, from Hund's rules and the Pauli principle, each of the seven Ni II sites have a three-fold multiplicity associated with different z-axis projections. This results in 1 having 3 7 =2187 basis states. In this study, we have used these 2187 basis states to solve the following magnetic Hamiltonian exactly,