Common Structure Types

Figure 4.1 shows the common structural types that describe a very large number of inorganic molecules. Linear, trigonal planar, tetrahedral, trigonal bipyramid, and octahedral structures result when... 

During the study of inorganic chemistry, the structures for a large number of molecules and ions will be encountered. Try to visualize the structures and think of them in terms of their symmetry. In that way, when you see that Pt2+ is found in the complex PtCl42 in an environment described as D4h, you will know immediately what the structure of the complex is. This "shorthand" nomenclature is used to convey precise structural information in an efficient manner. Table 5.1 shows many common structural types for molecules along with the symmetry elements and point groups of those structures. 

A selection of frequent stoichiometries and common structural types found within the binary intermetallic compounds of the alkali metals is given in Table 5.6. 

Table 5.10 summarizes the data relevant to a few selected compositions and more common structure types of the phases formed in the binary alloys of Ca, Sr, Ba, Eu and Yb. Considering the alloys given by the elements of the different groups, some remarks can be made on the following points ... 

Remarks on the alloy crystal chemistry of the 4th group metals. Selected groups of isostructural phases, pertaining to simple common structural types have been collected in Table 5.25. A number of them (for instance CsCl, AuCu types, Laves phases, AuCu3 type) correspond to more or less extended solid solution... 

Examples of common structure types and of their characteristic fragments In Chapter 3 it was underlined that several interrelations between different structures may be described in terms of recombination structures , evidencing the structural... 

In this paper only the aspects of structural chemistry of the more common structure types adapted by fluorine compounds will be considered. There wiU also be a brief account of the cooperative phenomena of antiferro- and ferrimagnetism, that are strongly dependent on crystal structures. For all information on preparation and chemical properties of transition metal fluorocomplexes, especicilly interesting for the high valency states, the reader is referred to the excellent reviews given by Sharpe (278) and by Peacock (255). 

We see in the AB structure map at the end of the book that the two most common structure types, NaCl and CsCl, are well ordered into separate domains. The ionic alkali halides containing NaCl and CsCl are themselves located in the upper left-hand corner of the map. Running across to the right... 

Binary Ionic Solids Common Structural Types... 

Recent developments in the synthesis, structures, and properties of ionic/covalent ternary nitrides are reviewed. A description, including synthetic conditions, is given of preparative methods reported in the literature. Solid state synthetic reactions from binary nitrides as well as novel synthetic approaches such as amide synthesis and ammonolysis of ternary oxides are described. Examples of common structure types as well as electronic and magnetic properties are discussed. 

Body-centered cubic packing (bep) is a common structure type among metals. The space group is 0 -Im3m, and the atomic coordinates of equivalent positions are listed in Table 10.3.1. 

The existence of the third tautomer cannot be neglected in any case. The position of every equilibrium is determined by the combined effect of polar and steric structural factors as well as by the medium. As long as no equilibrium is too far from the common structural type, all three forms may be present simultaneously. Even if both equilibria are shifted to the limit in favor of forms A or C, the intermediate existence of the carbinolamine must be taken into account. 

Structures for some common crystal types in which the ratio of cation to anion is 1 2. (a) The fluorite structure. The fluorite structure is a common structural type for 1 2 compounds. If the compound has a 2 1 formula, the role of the cation and anion are reversed, and this gives the antifluorite structure that is shown by compounds such as Na2S. (b) The Ti02 or rutile structure. 

The element halogenoanions are a structurally diverse group of compounds and will be considered in the following sections according to common structural types. There is no unique way in which to do this, but, throughout, the relationships between the various forms will be highlighted. 

AB2 Systems. Since layered structures are important variants in AB2 systems (e.g. the Cdl2 and CdCb families of structures), it was deemed necessary to always use a Coulomb potential without a damping term. The method chosen to perform the full Coulomb sum was the one suggested by de Leeuw66. Again, the resulting structure candidates in general did not depend on the exact values of the effective potential. The most common structure types found are summarized in table 3. We note that these include many commonly found structures like anatas,... 

Figure 6 Common structural types of compounds containing low oxidation state group 15 elements...

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