Perturbed matrix method calculations are performed on a diheme cytochrome c (DHC) protein, in order to assign previously experimentally detemined reduction potentials (E-0) to their corresponding heme groups. Very good agreement between calculated values to experimental data prove that the present approach can be used as a predictive tool of redox thermodynamic properties of multicenter redox proteins in the absence of experimental data, or in synergy with state-of-the art spectroscopic and electrochemical approaches to obtain a detailed picture of electron transfer processes within these complex systems.