Direct summation of Madelung energies

A computerized procedure based on the Evjen method for the direct summation of Madelung energies of centrosymmetric structures is described. The values obtained are strictly according to the definition of the Madelung function and the accuracy depends only on the number of terms taken into consideration. Madelung energies for a variety of structures calculated by this method are compared with values obtained by various other methods.