Summary of Structural Data

The structural data for silicon carbide is summarized in Table 7.3.1 1 

Polytypes Density (g/cm ) Lattice a (nm) Parameters c (nm) Space Group 

It should be noted that the hexagonal cell parameter of a aSiC polytype remains essentially constant while its varies as = x 0.2518 nm (with slight differences), where n is the number of double layers of SiC in the hexagonal cell.O l 

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Summary of structural data for rare earth carbonates. 

Summary of structural data on rare earth siUcates. 

Summary of structural data on rare earth complexes containing halogen oxoanions. ... 

Summary of structural data on solid octa-aqua and hexa-aqua complexes of the rare earths. 

Table 2.2. Summary of structural data for complexes of perylene (Per), with simple inorganic anions...

Some efforts have been made to interpret the spectroscopic and magnetic properties of cobalt enzymes in terms of coordination geometry and chemical identity of ligands. The basis of these attempts is a comparison with the corresponding properties of low-molecular weight complexes of known structure. A brief summary of relevant data on some models is given in the following section. 

Several of the reference texts and review articles on kinetics give discussions of entropies of activation in terms of structure and mechanism, and it is sufficient here only to refer briefly to a few of them. Values of AS (or its equivalent, frequency factors) for unimolecular gas reactions have been considered in some detail (Benson, 1960b Frost and Pearson, 1961c Gowenlock, 1960). Summaries of thermodynamic data for solution reactions may be found in several sources (Frost and Pearson, 1961d Moelwyn-Hughes, 1947 Pearson, 1952). 

Unlike neutron data, X-ray data do not show the positions of hydrogen atoms, and the orientation of the water molecules cannot be directly determined, which, on the other hand, can be an advantage for the derivation of the structure beyond the first coordination sphere, since the absence of hydrogen contributions will reduce the number of overlapping peaks in the RDFs. A summary of structure determinations of aqua ions from X-ray diffraction measurements on solutions is given in Table III (41-143). Results reported for the alkali metal ions, Cs+ (73-75), Li+ (100), and Na+ (109-111), which have less distinct hydration spheres, have not been included in the table. 

This section of the review of DOM in freshwaters will examine its isolation by XAD resins and by membranes, the molecular weight distribution of DOM, its elemental composition, its acidic functional groups, its distribution of carbon among structural subunits, and the low-molecular-weight molecules (amino acids, sugars, and lignin-derived phenols) that are liberated from DOM by hydrolysis or oxidative degradation. For each of these subtopics, a statistical summary of published data will be presented. 

Tables 1 and 2 present a summary of available data, obtained both by experiment and by calculation methods "-" for nitrides and carbides with the cubic-NaCi and hexagonal wurtzite structures.

An excellent summary of — M data by Fetters et al. provides estimates for these parameters in both 6 and good solvents for a number of linear polymersJ The parameters in Eq. (19) are not only influenced by the experimental conditions (solvent, temperature) but are also affected by the polymer s structure. For monodisperse stars, it has been found that increasing the number of arms decreases K g while u remains identical to that of the linear polymer (see Fig. 1). However, for randomly branched polymers, it has been found that u is closer to 0.5 and in some cases much lower. Such low values of this exponent might be considered as an indication of the branched polymer being in an unperturbed state however, this is not the case. An explanation as to why u is so small for randomly branched polymers has been found using fractal behavior, and an overview is given by Burchard. ... 

Table 1. Crystal Data and Summary of Intensity Data Collection and Structure Refinement...

The summary of the data at this point seemed to indicate that the combination of good nucleation efficiency with the BT-structures and the advantage of high P-values seem to... 

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