The Knight Shift in Liquid Binary Alloys: An Application of Quantum Chemistry in Liquid- and Solid-state Physics

We outline a model for calculating the Knight shifts of Na-23 and Li-7 nuclei in liquid sodium-lithium alloys. The model used for the calculations is based on the "multiple-scattering" model (self-consistent scattered wave). Bearing in mind that there exists an uncertainty of about 5-10% in the values of the susceptibilities of sodium and lithium, the calculated values of the Knight shift of Na-23 in bcc Na and fcc Na (0.159% and 0.185%, respectively) are in good agreement with the experimental values of the Knight shift at the melting point and at 400 degrees C (0.116% and 0.121%, respectively). The calculated value of the Knight shift K of Li-7 in fcc Li is somewhat larger than the experimentally determined Knight shift in pure Li at 400 degrees C: 0.033% and 0.026%, respectively. The theoretical calculations of the relative change Delta K/K-0 of the Knight shifts of sodium and lithium nuclei in NaLi alloys as a function of the atomic concentration C-Na re in reasonable accordance with the experimentally known linearity between Delta K/K-0 and C-Na.