Abstract
A simple theory whose forte has been the determination of structures and energy levels for large nonionic systems is found to be applicable to ionic systems when the effects of self‐consistent charge transfer are incorporated. The theory confirms the LEEDstructural analyses for O, S, and Se on Ni(100) and S on Ni(111) as found by Demuth, Jepsen, and Marcus. Further, the atomic valence ionizationenergy shifts are in agreement with the surface oxide photoemission spectrum of Conrad, Ertl, Küppers, and Latta.