Determination of the 207Pb Chemical Shift Tensor in Crocoite, PbCrO4, Using Single-Crystal NMR Spectroscopy

The full chemical shift tensor of 207Pb (spin I=1/2) in the natural mineral crocoite, PbCrO4, has been determined using single-crystal NMR spectroscopy at room temperature. The eigenvalues of the tensor in its principal axes system are δ11=−2720±2 ppm, δ22=−2319±4 ppm, and δ33=−1830±5 ppm, resulting in an isotropic chemical shift of δiso=−2289±2 ppm. Additionally, these values were verified using a Herzfeld–Berger analysis of a polycrystalline sample under magic-angle spinning (MAS) conditions.