Supplementary Material for on-line publication

The supplementary material contains definitions of triplet molecular spin functions, Zeeman Hamiltonian, plots of energy gaps between adiabatic states, first derivatives of adiabatic energies, adiabatic energies of Ni(dpp)Cl2 model in the weak and strong field regimes, magnetic field effect as a function of internal energy for Ni(dpp)Cl2 calculated with giso =2.1121546, transition probabilities for Ni(dpp)Cl2 in the strong field regime, total rate constant of the Ni(dpp)Cl2 isomerization as functions of internal energy, Fortran code, and the input files for NAST calculations.