Because of the non-innocent character of the corrole ligand, multiplicity studies were performed to evaluate the spin state of the minimum energy structures showing different values in each case (Table ). The spin density surfaces are plotted in Fig. according to minimum energy spin states. A ferromagnetic nature is found in compounds C1, C2, C3, C6, and C7, which display triplet spin-state (2S+1=3) and positive values of the magnetic exchange constant (J), oscillating between 3 to 82 cm -1 . Conversely, an antiferromagnetic ground state is found for compounds C4 and C5. Noteworthy is the antiferromagnetic behavior of C5 since it displays the stronger coupling of -1168 cm -1 that agrees with the high overlap between α and β unrestricted corresponding orbitals (UCOs), reaching 25 % on the whole molecule (Fig. ). This overlap is allocated on the Cu center, in contrast to the strong ferromagnetic case (C7), showing no overlap on the metal center and reaching only 1.25 % of overlapping on the whole molecule (Fig. ). for each surface.