By analyzing the potential energy surface between the S 0 and T 0 geometries, the highly multiconfigurational nature of the S 0 state at the saddle geometry is shown to gradually reduce as the molecular geometry approaches the more planar T 0 geometry. Additionally, for the unsubstituted copper corrole, degeneracy is observed at the planar geometry between the S 0 and T 0 states, however, the degeneracy is lifted at the triphenyl copper corrole, which is consistent with the reduced planarity.