We report the observation of structure on the ground state hyperfine levels of Eu 3 + in Nd 3 + : EuCl 3 · 6 H 2 O using Raman heterodyne detected nuclear magnetic resonance. The strength of the interaction varied for different satellite lines in the spectrum of the F 0 7 → D 0 5 transition of Eu 3 + . The structure is attributed to magnetic dipole–dipole interactions with Nd 3 + , and it is proposed that these interactions can be used to associate the satellite lines with the positions of the Eu 3 + ions relative to the Nd 3 + ion. We discuss the implications of these measurements for quantum computing applications of stoichiometric crystals.