Charge transfer and stability of NFE random alloys

The stability of random alloys is determined primarily by a balance between the energy of the volume change upon alloy formation (elastic energy), and the charge transfer between atomic cells. The charge transfer in homovalent, nearly free electron alloys was determined by taking the wave function to be that of the free atoms inside the ion cores, and to be plane waves in the interstitial regions. For a given valence, it was possible to establish an electronegativity series based on charge transfer, to determine charge transfer as a function of composition, and to compute the energy of alloy formation. The theory properly accounts for the formation of alloys of the alkali and alkaline earth metals, and shows why so few such alloys form.