Rationalization of Complex Geometries

We shall return to this topic in Chapter 9. Remember that the unequal distribution of electrons within bonds results in a continuous variation from covalent to ionic bonding. 

Box 1-3 These are the polyhedra which are used for the basic structural types  

If the central atom has different groups or atoms around it, or if one or more of the vertices of the polyhedron is occupied by a lone pair, then variations in bond angles will occur such that distorted polyhedral arrangements are obtained. In its quantitative forms, the VSEPR model parameterizes each individual interaction and makes very accurate predictions of the distortions which are to be expected. 

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