A SIMPLE PROCEDURE FOR THE DETERMINATION OF THE QUADRUPOLE INTERACTION PARAMETERS AND ISOTROPIC CHEMICAL-SHIFTS FROM MAGIC ANGLE SPINNING NMR-SPECTRA OF HALF-INTEGER SPIN NUCLEI IN SOLIDS

A simple procedure is presented for the determination of the asymmetry parameter of the electric field gradient, the quadrupole coupling constant, the second-order quadrupolar shift and the isotropic chemical shift of quadrupolar nuclei with half-integer spin directly from the experimental magic angle spinning (MAS) NMR spectra of powder samples measured at a single magnetic field. General equations applicable to any half-integer spin nucleus and the specific expressions for Na-23 and Al-27 are given. The simple calculations can easily be performed with a pocket calculator and avoid any spectral simulation or lengthy computer work. The method was applied to a series of Na-23 MAS NMR spectra of selected sodium compounds and the agreement of the results with those of computer simulations is demonstrated.