On the Herzfeld Theory of Metallization. Application to Rare Gases, Alkali Halides, and Diatomic Molecules

Abstract

In 1927 Herzfeld proposed a criterion which predicted that an element would become metallic when its molar volume became equal to or less than R, its molar refractivity. We have inspected this criterion by comparing its predictions with calculations on the rare gases and hydrogen, and with high pressure experiments on iodine and the alkali halides, and found it to be surprisingly good.