Calculations of the hyperfine parameters of bond-centered muonium in diamond

The electronic structure of hydrogen and muonium at the bond-centered site in diamond is investigated using ab initio cluster calculations. Correlation effects are accounted for by a configuration interaction expansion and by the local density approximation in the density functional approach. The hyperfine and superhyperfine parameters for anomalous muonium are determined by averaging over the spread of the muon wave function. Good agreement with experimental hyperfine parameters is found.This work has partially been supported by the Swiss National Science Foundation.