Since the nuclei do not have time to move during the quick electron jump, the two new species created when an electron jumps from one reaction species to another are in the incorrect environment of the solvent molecules and chemical structure of the reactants. The system reaches the ground state of the product after fluctuations (nuclei relaxation) take place. In Fig. , a profile of the free energy surface is provided for several instances. The abscissa is a multidimensional configuration coordinate. Two parabolas represent the energy profile of reactant (solid line) and products (dashed line). Overall, the electron transfer takes place in an inverted Marcus region if the crossing point of two parabolas happens outside of the two minima range (see Fig. Single-minimum energy surface appears when the electronic interaction is strong enough to be greater than the activation barrier free energy (see Fig. A significant change in the Fermi-level energy in smaller supercells with respect to their charge state is shown in Fig. (a). As N , the number of carbon atoms in the supercell, increases, we observe that the variation decreases. Therefore, for the electrode to maintain a constant potential, the size must be infinite. However, we utilize a supercell of 15 × 9 unit cell containing 540 carbon atoms whose Fermi-level energy varies less than 130 meV between two successive charge states. In Fig.