The one−electron energy level structure for single complexes of Al2O3 and Al2O2N are calculated using the multiple−scattering Xα method of Johnson. The results of our calculations on Al2O3 are in qualitative agreement with the band structure calculations of Douglas on α−Al2O3. The results of our calculations on the Al2O2N complex suggest that a nitrogen atom substituting for an oxygen atom in sapphire may act as an electron trap or, under either thermal or photon excitation, as an acceptor center. From our calculations the optical spectrum expected for a neutral Al2O2N complex in sapphire is predicted.