The Knight shift in liquid ternary and binary alkali allovs

New experimental data on ternary K-Rb-Cs and Na-Rb-Cs alloy systems, including binary Na-Cs and Na-Rb alloys, are presented. The ternary alloys were chosen because they offer the intrinsic possibility of constructing alloy systems for which the Knight shift of one of the components, or the atomic volume, is independent of concentration. The experimental data are discussed in terms of an extended single-APW model and are also compared with the results of recently published pseudopotential calculations. A survey of existing estimations for the spin susceptibility of alkali metals is given. Finally, the possibilities for a consistent description of the Knight shift, involving both the nuclear contact density and the susceptibility, are investigated.