Crystalline Compounds with AB Stoichiometry

Two different atoms, A and B, have different radii, different electronic configurations and different electronegativity. All these three properties have their say regarding the ordering of the two partners in the solid state the present discussion follows (Chiriac-Putz-Chiriac, 2005). 

The electronic configurations of partners are those that impose the mixing ratio x/y it should provide greater stability for each produced by a reaction species as well as the electroneutrality of the system. 

For the main group elements, the (AB) compounds with x y = 1 stoichiometry correspond to the isoelectronic horizontal series, with the interactmg elements symmetrically placed in relation to group IVA, see Table 4.3 (Chiriac-Putz-Chiriac, 2005). 

In an isoelectronic horizontal series, one is remarking that with the increasing AZ of the elements, increases also the atoms electronegativity difference (A ) so emphasizing on the ionic character of the interaction. 

This increase is manifested also in the increasing tendency of compaction of the arrangement, i.e., the increasing of the coordination number of partners. Starting from a compound of a horizontal isoelectronic series, vertical isoelectronic series are obtained by substitution of one of 

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