Vibrationally averaged β-hyperfine coupling constants for the muonium-substituted ethyl radical

Abstract

A variation-perturbation approach is applied to compute isotope-dependent zero-point vibrational corrections to the β-hyperfine coupling constant of the ethyl radical. The corrections increase the coupling by ca. 5, 7 and 23% for the deuterium-, protium- and muonium-substituted radicals, respectively. The large vibrational correction to the muon β-hyperfine coupling constant could explain the ‘residual’ isotope effect observed experimentally.