These results can be qualitatively rationalized from the shape of the HOMO and LUMO orbitals for a single [8]CPP molecule (see Fig. ). For instance, in the HOMO level, the lobes of orbitals show a node every half phenyl monomer unit (see Fig. ) which translates to the behavior of electronic coupling values displayed in Fig. . The largest electronic coupling arise from the bonding or antibonding combinations of these orbitals in a dimer configuration. Another situation where the global overlap between the involved molecular orbitals becames key is for the perfect tubular orientation (see Fig. ). As can be seen in Fig. , unlike the HOMO which is localized on the phenyl carbon atoms, the LUMO level presents lobes at the H-edges, which translates to a dominant overlap in the LUMO level of the dimer, helping to explain the discrepancies between t e and t h for that case.