Prediction of refractive index of inorganic compound by chemical formula

A method is proposed for estimation of mean refractive index of a compound which chemical composition is known. This method is based on using of systems of electronic polarizabilities of ions and ionic radii in crystals. Applicability of the method has been tested for a representative set of ∼100 known inorganic noncentrosymmetric crystals. It has been shown that mean refractive index can be predicted with possible error of 0–30% depending on the chemical nature of the compound. The majority of oxides show acceptable difference <20% between theoretical and experimental refractive index values and mean error level for a set of 63 oxide crystals is as low as ∼9%.