Temperature-dependent diamagnetic amplitudes from radio-frequency muon spin-resonance data on moderately or heavily doped n-type samples implied the presence of MuT-. It was deduced that the muonium would be a negative-U impurity only if the energy difference between the MuT0 and MuBC0 configurations was less than 0.35eV. The Mu(0/+) thermodynamic level correlated well with results for monatomic H, but the Mu(-/0) level was estimated to be shallower than was claimed for H(-/0). The muonium data revealed a complicated set of transitions which were active during the muon lifetime, and involved 4 separate muonium states.

Dynamics of negative muonium in n-type silicon B.Hitti, S.R.Kreitzman, T.L.Estle, E.S.Bates, M.R.Dawdy, T.L.Head, R.L.Lichti: Physical Review B, 1999, 59[7], 4918-24