Van der Waals, hydrogen bonding ion-dipole and Coulomb energies in crystals

Some potentials describing electrostatic and ion-dipole interactions have been tested in known crystal structures for use in a general solution of the phase problem. Sodium tetrazolate monohydrate (Na+HCN-4.H2O) has been considered to assess qualitatively the contribution of the various forces stabilizing the crystal lattice. In spite of the competitive effect among different energy terms the actual structure agrees satisfactorily with the deepest energy minimum. Sodium, potassium and rubidium azides (NaN3, KN3 and RbN3) have been investigated to obtain qualitative potentials for alkali ions and charged nitrogen atoms.