Moment analysis as a systematic tool for NMR powder pattern analysis

The low order moments for chemical shift and second-order quadrupolar powder patterns have been calculated as functions of the anisotropy and asymmetry parameter of the governing interaction, and the expressions inverted to give these parameters as a function of the moments. Theoretical simulations and experimental experience show that moment analysis in most cases equals and in some cases exceeds the accuracy of direct inspection as a method of obtaining NMR parameters. We illustrate the efficacy of the method applied to P-31 chemical shift spectra of nucleic acids, and K-39 second-order patterns of series of potassium salts. (C) 2000 Elsevier Science B.V. All rights reserved.