Polyhedra linked

Limits of the mutual rotation of vertex-sharing tetrahedra and of vertex-sharing octahedra and the resulting bond angles at the bridging atoms. The minimum distance between vertices of different polyhedra (dotted) was taken to be equal to the polyhedron edge 

Inorganic Structural Chemistry, Second Edition Ulrich Muller 2006 John Wiley Sons, Ltd. 

The way in which polyhedra will join depends on several factors, which include  

Chemical composition. Only very definite patterns of linking polyhedra are consistent with a given composition. 

Bond polarity. Very polar bonds do not harmonize with edge-sharing polyhedra and 

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What Hermann-Mauguin symbols correspond to the linked polyhedra shown in Fig. 16.1 (p. 166) ... 

General characteristics of alloys such as those presented in Fig. 3.3 have been discussed by Fassler and Hoffmann (1999) in a paper dedicated to valence compounds at the border of intermetallics (alkali and alkaline earth metal stannides and plumbides) . Examples showing gradual transition from valence compounds to intermetallic phases and new possibilities for structural mechanisms and bonding for Sn and Pb have been discussed. Structural relationships with Zintl phases (see Chapter 4) containing discrete and linked polyhedra have been considered. See 3.12 for a few remarks on the relationships between liquid and amorphous glassy alloys. 

In layer structures, the number and availability of bonds to the nearest neighbours is decided by the electrons available as stipulated by valence theory. Layer structures based on linked polyhedra are the most common ones in catalysis. Some of these are described below. 

Many other linked polyhedra similar to molecular boranes are found for B-rich solid compounds of alkali and alkaline-earth metals. There are octahedra in Li2B6, octahedra and pentagonal bipyramids in Na3B2o, dodecahedra and bicapped square antiprisms in U3B14 and icosahedra in Na2B29. The cluster connection is particularly clear for compounds of this type. 

These two rules can be discussed together, since Rule 4 is obviously a corollary of Rule 3 both rules deal with systems of linked polyhedra and, in Pauling s original formulation, the absence of shared elements is attributed to the destabilizing effects of cation-cation Coulombic repul-... 

Tossell, J. A., and G. V. Gibbs (1977a). A molecular orbital study of shared-edge distortions in linked polyhedra. Amer. Mineral. 61, 287-94. 

This approach has been particularly developed for application to macropolyhe-dral structures, clusters involving linked polyhedra, and many examples have been described in detail. ... 

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