Note that in this geometry, the molecular orbitals labeled d x 2 -y 2 and π b 1 have orbital overlap between the d x 2 -y 2 orbital and the π orbital, which is the driving force for the large saddling angles described previously. Therefore, one cannot strictly assign a copper oxidation state to each configuration since some of the charge density for occupying the orbital labeled "d x 2 -y 2 " is in fact on the ligand. For the unsubstituted copper corrole studied with the (4e,5o) active space, the (π a 2 ) 2 (π b 1 ) 1 (d x 2 -y 2 ) 1 configuration contributes 53.6%, while the (π a 2 ) 2 (π b 1 ) 2 (d x 2 -y 2 ) 0 and (π a 2 ) 2 (π b 1 ) 0 (d x 2 -y 2 ) 2 configurations contribute 30.4% and 11.0%, respectively (Table ). Similar values of 50.1%, 33.4%, and 11.9% are obtained for the same configurations in the triphenyl-substituted system. One can already see that the system is highly multiconfigu-rational and, based on the weight of the configurations obtained, the oxidation state of the copper is clearly not pure Cu(II) or pure Cu(III), consistent with previous reports.