Regularities in melting points of lithium halides: is LiH anomalous?

摘要

Using experimental data for the melting temperature T_m for four Li halides (F to I), it is demonstrated that T_mZ~(1/3) is close to constant, approx= (2530 ± 250)K, where Z is the atomic number of the halogen. This formula is not appropriate for what sometimes is considered the simplest halide, LiH, and therefore alternatives are investigated which involve a characteristic electrostatic energy e~2/εS, with S the internuclear separation and ε the static dielectric constant.