Prediction of refractive index in inorganic crystals based on averaged atomic mass

Abstract

The correlation between the refractive index and the averaged atomic mass of inorganic insulators was analysed. It was shown that the correlation allows to predict the refractive index with a mean absolute error of 4,4% for the considered set of 238 compounds containing no transition metals or halide ions. A further significant improvement in the accuracy of predictions and the possibility of including fluorine compounds can be obtained by introducing a correction proportional to the content of the selected chemical element in the molecule. The proposed prediction method is not related to the structure of the compound, is extremely simple and does not require any other data apart from the chemical formula.