Kapustinskii equation

The Kapustinskii equation is used to determine the lattice energy of salts, which can not be or is difficult to determine experimentally. According to Anatoly Kapustinski, who published the equation in 1956, this applies to the lattice energy:

In this case, and the radius of the anion and the cation in angstroms, and the charge of the anion (<0 ) or cation (> 0) and the number of particles per formula unit. The Kapustinskii equation can, however, also use for the determination of atomic radii, if the lattice energy is known, which is a particularly complex ions such or extremely useful. Even if the lattice energy with this formula can not be calculated exactly, they are still a good approximation, since the deviation is usually below 5%.