Large-scale simulations of the finite-temperature properties of the molecular assemblies Mn6 and Ni12 Original Research Article

The numerical transfer-matrix approach and the exact diagonalization technique are worked out for the isotropic Heisenberg model with the uniform and alternating spin variables within the ring geometry. They are applied in large-scale simulations to the above cyclic organometallic clusters Mn6 (i.e. [Mn(hfac)2NITPh]6) and Ni12 (i.e. Ni12(O2CMe)12(chp)12(H2O)6(THF)6) in order to quantitatively model their magnetic properties. For the Ni12 complex new experimental data are also reported. The microscopic spin model parameters for both molecules are obtained from a fit of the theoretical curves to the experimental results.