Calculations of the localized electronic defect states, due to tetrahedral and hexagonal interstitials and vacancies, were performed by using both an sp3 and an sp33d5 valence band basis set which took full account of orbital overlap. Both cation and anion defects were considered. The effects of the Cd d-orbitals upon the formation of localized defect states were analyzed.

J.T.Schick, C.G.Morgan-Pond, J.I.Landman: Materials Science Forum, 1992, 83-87, 1253-8