DETERMINATION OF QUADRUPOLE COUPLING TENSORS FROM SINGLE-CRYSTAL NMR DATA

A brief description is given of a general procedure which we have used for a number of years for the analysis of NMR quadrupole splittings and chemical shift data from single crystals. Some of the advantages of the procedure are: (1) It includes, in a simple straightforward way, all possible restrictions imposed by crystal symmetry on the efg tensors and on relations between efgtensors of symmetry-related atoms. (2) When the crystal orientation is unknown or known with insufficient precision, the procedure allows a determination of the orientation fully or in part, depending on the crystal symmetry. (3) The procedure permits the analysis of data from rotation patterns obtained by rotating the crystal(s) about an arbitrary number of axes, not necessarily mutually orthogonal and not necessarily orthogonal to the magnetic field direction. The use of the method is illustrated by examples from determinations of deuteron quadrupole coupling tensors in some hydrates. In all cases the full efg tensors were determined from rotations about one, two, or three axes. © 1978.