Naming shapes

The contribution of Parr and Bartolotti is not diminished by these precedents they were the first to recognize that o-(r) is a quantity of interest in its own right, separate from the electron density [1], They also deserve credit for coining the name, shape function, which captures the essence of the quantity and provides an essential verbal handle that facilitated future work. 

The design of molecule-based magnets requires the assembly of magnetic bricks in a controlled fashion. The bricks we play with are characterized by three factors, namely shape, chemical functionality, and spin distribution. The first two factors are common to all bricks (or building blocks) used in molecular chemistry. The third is specific to molecular magnetism. Spin distribution is a new dimension. Let us consider the brick [Cu(opba)]2- (where opba stands for ortho-pheny-lenebis(oxamato)) this is shown below as a typical example [6, 7]. 

Selenite which shines like the moon, and hence its name, shaped like the specular stone, or Mary s ice,... 

Idealized structures up to nine-coordination are summarized in Figure 4.21. These do not represent all of the shapes met, since, apart from all these idealized structures, it is necessary to remember that bond angle and bond length distortions of these structures can occur some of the shapes resulting from these effects are themselves common enough to be represented as named shapes, and we have discussed some examples of these earlier. Further, beyond nine-coordination, an array of additional shapes can be found, of which perhaps the best known are the bicapped square antiprism (for ten-coordination), the octadecahedron (for eleven-coordination) and the icosahedron (for twelve-coordination). Clearly, the options are extensive, so it may be time to find out what directs a complex to take a particular shape. 

Excitations similar to giant resonances are observed for much deeper-shell excitation, and are more aptly named shape resonances, because the spatial overlap between the initial and final states is less complete than for giant resonances. An example is 3d — f in Ba, which is similar in character, but not identical, to Ad —> / in the same element in particular, the smaller spatial overlap means that the exchange integral has a less dramatic influence on the spectrum, which is why, when studying solids (see chapter 11), deep shell excitation is preferred if the resonance is to be used as a probe of final state density in this way, one avoids most of the term dependence. 

As noted in Section 7.3, shape resonances also occur in the spectrum of vibrational transitions. They correspond to predissociation by rotation (resonances stabilized behind the nuclear motion centrifugal barrier, Vj(R)). Here the name shape resonance comes from the shape of the barrier on Vj(R). 

For the zeolite catalysts, another factor dominates, namely shape and size of the zeolite pores. The shape of the product molecules is governed primarily by the pore structure of the zeolite catalyst. 

Name Shape subparticle location High-energy Low-energy... 

Name Shape function Unit Description Shape frame Selection... 

Anchors without end plates (Fig. 11) consist of a metallic profile that is embedded in the masonry and can transmit loads to the substratum by mechanical locking, friction, bond, or a combination of these three (EUgehausen et al. 2006), rather than use of an element such as a plate, a key, or a peg. Mechanical locking can be obtained, for instance, by undercut, namely, shaping the end part of the hole and introducing an anchor with an end shape so as to result larger than the rest of the shaft. Friction systems, instead, consist of torsion or displacement-... 

The Wiener double refraction is indicated by the name shape double refraction or also according to the structure of the system by rod- or disc double refraction. Since however we arc here always concerned with oriented structures, we must include it as a special case in the classification orientation double refraction ... 

Trade name Shape of tubes (maker) Chemical composition (mass%) Tensile properties (RT) ... 

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