Theoretical studies of electronic defect states in amorphous and amorphous hydrogenated material were reviewed. The theoretical methods were treated within 1-electron theory. The defect states included weak bond, impurity, dangling bond, and impurity-dangling bond complexes. The charge densities of a weak bond and of an impurity-dangling bond complex were presented.

C.Y.Fong, L.H.Yang: Solid State Phenomena, 1995, 44-46, 657-66