Calculation and Interpretation of the NMR Chemical Shift and Its Pressure Dependence in the Alkali Halide Lattices

Abstract

The symmetrical orthogonalization technique of Löwdin has been applied to the alkali halide outer‐shell s and pwavefunctions. The resulting distorted ionic wavefunctions have been used to calculate the pressure dependence of the NMRchemical shift within the framework of the Kondo—Yamashita overlapping‐ion model. The computed values of the rate of change of the chemical shift with respect to pressure, the change of the chemical shift at the NaCl–CsCl phase transition, and the chemical shift of the ionic reference solutions are compared to Baron's experimental data. Reasonable agreement is found although discrepancies exist and are discussed. No adjustable parameters are used in these calculations.