1ST PRINCIPLES CALCULATIONS OF HYDROGEN IN BULK GAAS

We present the results of first-principles calculations of the properties of neutral (H0) and charged (H+ and H-) hydrogen in bulk GaAs. The equilibrium sites are determined, and the electronic properties for the equilbrium positions are studied. H+ behaves as a deep donor and prefers to stay in a high valence charge region which includes the bond center. H- behaves as a deep acceptor and prefers the low valence charge region near a tetrahedral site. H0 has an amphoteric behaviour depending on the site it occupies. We compare our results with the results of calculations for H in Si.