Determination of the repulsion energy in ionic compounds

A method for determining the energy of the interparticle repulsion between ions is proposed based on a comparison of the experimental data for gas molecules and crystals of these substances. The available experimental data on the compressibility of the compounds with a crystal lattice of the $\rm{NaCl}$ type in the solid state are examined, and the repulsion energy is determined for a number of substances for which there are no data on their compressibility.