INTERSTITIAL MUONS AND HYDROGEN IN CRYSTALLINE SILICON.

Self-consistent total energy surfaces for H**30 , H**o and H//2 present interstitially in crystalline Si were calculated concluding that molecular hydrogen in the stable form, consistent with the lack of observed electrical and optical activity. Both H** plus and H**o have complex surfaces, with some features sensitive to lattice distortion. The local minima are too small to give localized states when zero-point energy is included. The results are discussed in relation to earlier theories and to experiments on ″normal″ and ″anomalous″ muonium left bracket mu ** plus e** minus right bracket .