Origin of the Singular Diameter in the Coexistence Curve of a Metal

Abstract

It is suggested that the large amplitudes of the singularities in the coexistence-curve diameters of cesium and rubidium, as measured by J\"ungst, Knuth, and Hensel arise from the correspondingly strong thermodynamic-state dependence of the screened ion-ion interactions in these systems, especially as the metal-insulator transition is traversed. This state dependence, which is normally negligible for typical insulating fluids, corresponds to the mixing of thermodynamic fields present in certain lattice models and scaling theories.