Molar Polarization and Radius-Ratio of Ions

Abstract

THE interionic distance in the crystalline state is not exactly additive for the radii of the constituent ions. Fajans¹ explains it in terms of polarization. Pauling², on the other hand, neglecting the effect of polarization, explains these deviations from additivity as the effect of the radius-ratio, ρ, of the constituent cation to anion. In this communication a set of empirical equations concerning molar volumes and molar refractions of alkali halides will be first presented. Making use of these empirical equations, I am able to assign definite values to polarization and obtain a function of ρ which, though different in form from Pauling's function, F(ρ), gives identical values.