Structural Stability of Suboctet Simple Binary Compounds

There are forty-five simple binary suboctet non-transition-metal compounds ANB^P-N ($3<~P<~6$) which crystallize in six crystal structures belonging to two broad families. We show that although these structures cannot be differentiated using isotropic atomic coordinates, successful topological separation is achieved using anisotropic bond-charge coordinates with sigma and π symmetry. Anisotropic bond-charge coordinates were previously used by St. John and Bloch to separate the five structures of 59 compounds of the prototypical ANB^8-N octet family.