First-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 equilibrium 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.