Clausius-Mossotti eqn. can be expressed as:rn(ε - ε0)/(ε + 2ε0) = Nα / (3V)rnwhere:rnε is the dielectric constant of the materialrnε0 is the permittivity of free spacernN is the number of polarizable molecules per unit volume of the materialrnα is the polarizability of a single moleculernV is the molar volume of the material