Nuclear Magnetic Resonance Powder Patterns in the Presence of Completely Asymmetric Quadrupole and Chemical Shift Effects: Application to Metavanadates

Abstract

A procedure was developed for the determination of the locations of shoulders and singularities of polycrystalline nuclear magnetic resonance (NMR) powder patterns in the presence of both nuclear quadrupole and anisotropic magnetic shift interactions. This determination was performed for both the satellites and the central transition of the NMR spectra of nuclei with half-integral spin I. Typical theoretical behavior of the powder pattern for the central transition in the presence of both quadrupolar and magnetic shift interactions is shown in a series of examples. In addition, a computer program was devised which calculated the powder pattern for arbitrary quadrupolar and magnetic shift parameters, convoluted it with a function that simulates the effects of dipolar broadening, and took the derivative of the result. The quadrupolar and magnetic shift parameters in three metavanadate compounds (NH4VO3, KVO3, and NaVO3) are determined using these methods.