with the tensors principal axes frame (PAF) rotated by 45 • ± 15 • with respect to the z axis of the PAF of the g tensor. This interpretation of the HYSCORE data is consistent with the ELDOR-detected NMR (EDNMR) spectrum shown in Fig. , from which we can extract a single splitting due to an effective hyperfine coupling to 1 H with A eff ( 1 H) = 13 ± 1 MHz.