Electronic states of oxygen in gallium phosphide

The "classical" model described by Dean and others does not account for a number of the important electronic properties of oxygen in GaP. I summarize here the major experimental results which are unsatisfactorily explained by this model and present a new "weak-bonding" model, which does agree with experiment. This new model, which is based on spin multiplets formed from the four neighboring gallium bond orbitals modified by weak coupling to the central O atom, provides a detailed explanation of the experiments including Jahn-Teller and Zeeman effects and optically detected magnetic resonance. © 1984 The American Physical Society.