# Kapustinski equation

The **Kapustinski equation** is used to determine the lattice energy of salts , which is difficult or impossible to determine experimentally. According to Anatoli Kapustinski , who published the equation in 1956 , the following applies to the lattice energy :

Here and are the radii of the anion or the cation in Ångström , and the charge of the anion (<0) or cation (> 0) and the number of particles per formula unit. The Kapustinskii equation can, however, also be used to determine ion radii , provided that the lattice energy is known, which is extremely useful for complex ions such as or . Even if the lattice energy cannot be calculated exactly with this formula, it still gives a good approximation, since the deviation is usually less than 5%.

## See also

## literature

- Anatoli Fjodorowitsch Kapustinski: In:
*Journal for physical chemistry. Department B: Chemistry of Elementary Processes, Structure of Matter .*Volume 22, 1933, pp. 257 ff. - Anatoli Fjodorowitsch Kapustinski: In:
*Žurnal fizičeskoj chimii*No. 5, 1943, p. 59 ff. - Anatoli Fjodorowitsch Kapustinski:
*Lattice energy of ionic crystals.*In:*Quarterly Reviews of the Chemical Society .*Volume 10, No. 3, 1956, doi : 10.1039 / QR9561000283 , pp. 283-294.