The electronic structure of hydrogen and muonium at the bond-centered site in diamond is investigated using ab initio cluster calculations. Based on a Hartree-Fock calculation, correlation effects are accounted for by a configuration interaction expansion. 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 and values for the superhyperfine interaction, which can be detected in ${}_{}{}^{13}{}_{}{}^{}\mathrm{C}$ enriched samples, are predicted.

• Received 4 September 1992

DOI:https://doi.org/10.1103/PhysRevLett.70.154