Madelung constant

Madelung’s electrostatic lattice sum for NaCl, shell by shell, and Evjen’s genuinely converging summation of it, contrasted with a naive truncated sum that does not converge.

Evjen’s method: converging the NaCl Madelung constant

Evjen's method: converging the NaCl Madelung constant

Madelung’s lattice sum: the electrostatic energy of rock salt

Madelung's lattice sum: the electrostatic energy of rock salt