On the interpretation of muon spin rotation and level-crossing resonance observations on the muonic ethyl radical

Analysis of the muon spin rotation (μSR) data for the muonic ethyl radical CH 2 MuĊH 2 yields β-hyperfine coupling constants in good agreement with the recent level-crossing resonance (LCR) measurements. Other coupling constants are predicted and await confirmation by LCR. The role of hyperconjugation in the ethyl radical is assessed by an ab initio molecular-orbital calculation.