We note that both of the spin-crossover steps involve natural orbital occupancies in the lower-spin states that deviate strongly from unity, implying that the Heisenberg-Diracvan Vleck Hamiltonian 56,57,58 and the Landé formula for spin-state energies of polymetallic magnetic molecules do not apply and should not be used (at least as models of these particular spin-crossover transitions) regardless of whether one considers the two magnetic centers to be the two chromium atoms or the two orbital pairs.