Spin-polarized local density functional cluster calculations were performed for substitutional Ni in Si, and Cu in GaAs, together with metal-H2 complexes. The Jahn-Teller distortion for Ni in Si led to a slight displacement along <100>; in agreement with electron paramagnetic resonance data. Several models for NiH2 were investigated, and it was shown that one (with H located at anti-bonding sites to 2 of the Si neighbors of Ni) had the lowest energy and exhibited H-related local vibrational modes which were close to those reported for Pt-H2. A similar structure was found for CuH2 in GaAs. The electronic properties of the complexes were described in terms of a vacancy model for metal impurities.

R.Jones, J.Goss, S.Oberg, P.R.Briddon, A.Resende: Materials Science Forum, 1995, 196-201, 921-6