Metal-ammonia solutions

In dilute solutions of alkali metals in ammonia electrons are localized in cavities in the solvent, and thermodynamic and transport properties are very similar to those found for dilute solutions of strong electrolytes. At higher concentrations the properties deviate markedly from those of electrolyte solutions and approach those of a liquid metal. In this paper we propose an explanation for cavity formation, and discuss the metal-non-metal transition in the light of recent information about the transition in vanadium oxides and doped semiconductors.