Calculation of Knight shifts for liquid binary alloys of simple metals: charge-transfer effects

Abstract

The authors examine the calculation of the direct contribution to the electron spin density at a nucleus in liquid binary alloys of simple metals by low-order pseudopotential perturbative methods. It is concluded that self-consistency requirements are sufficiently stringent so that it is simply impractical to use this approach and expect reasonable accuracy. Hence, in order to gain some physical insight into the problem, a simple model, using the concept of a charge transfer between ions, is proposed for the estimation of the total electron contact densities at a nucleus in the alloy. The results are applied to determine the concentration dependence of the corresponding Knight shifts and good agreement is found with observation.