Overall, we observe that the predicted ground state is strongly dependent on the amount of Hartree-Fock exchange in a functional. One would hardly be able to identify the ground spin states of various intermediates formed along the catalytic cycle only with DFT. Calculations with more accurate wavefunction theory methods might identify the ground spin state of these intermediates with more certainty, but such computations would also be much more -if not prohibitively -expensive for such large molecular systems. Also, relatively small energy gaps between different spin states predicted with some versions of the density functional, comparable to the scale of thermal fluctuations (~kT), might imply that different spin states may coexist at equilibrium, and that ratio of different spin forms may be highly sensitive to various conditions, such as temperature, as well as modifications of the structure of the ligand. To the best of our knowledge, no experimental studies have addressed these issues of relative stability and possible coexistence of various spin forms of the Mnporphyrin catalytic complexes.