Prism linked

The ZrPt2Al structure type is a superstructure of the TiAs type, where the R atoms occupy the Ti positions. The Zr atoms form trigonal prisms, linked similarly as in the AIB2 structure. The prisms are alternately occupied by A1 atoms and pairs of Pt atoms. So the ZrPt2Al structure may be considered as a derivative of the AIB2 structure type where in every second prism there are two atoms instead of one. 

The II phase is similar to the / phase and contains layers of trigonal prisms linked at the top. The Rh atoms are in the centers of them. But the stacking of layers is different in the two strucmres. 

The radius of the 24-coordinate metal site in MBs is too large (215-225 pm) to be comfortably occupied by the later (smaller) lanthanide elements Ho, Er, Tm and Lu, and these form MB4 instead, where the metal site has a radius of 185-200 pm. The structure of MB4 (also formed by Ca, Y, Mo and W) consists of a tetragonal lattice formed by chains of Bs octahedra linked along the c-axis and joined laterally by pairs of B2 atoms in the xy plane so as to form a 3D skeleton with tunnels along the c-axis that are filled by metal atoms (Fig. 6.11). The pairs of boron atoms are thus surrounded by trigonal prisms of... 

Boron chains linked to form open nets trigonal prism Zigzag chains with side chains trigonal prism... 

The linking pattern of two zeolites is shown in Fig. 16.24. They have the /I-cage as one of their building blocks, that is, a truncated octahedron, a polyhedron with 24 vertices and 14 faces. In the synthetic zeolite A (Linde A) the /3-cages form a cubic primitive lattice, and are joined by cubes. j3-Cages distributed in the same manner as the atoms in diamond and linked by hexagonal prisms make up the structure of faujasite (zeolite X). 

IR spectrometers have the same components as UY/visible, except the materials need to be specially selected for their transmission properties in the IR (e.g., NaCl prisms for the monochromators). The radiation source is simply an inert substance heated to about 1500 °C (e.g., the Nernst glower, which uses a cylinder composed of rare earth oxides). Detection is usually by a thermal detector, such as a simple thermocouple, or some similar device. Two-beam system instruments often work on the null principle, in which the power of the reference beam is mechanically attenuated by the gradual insertion of a wedge-shaped absorber inserted into the beam, until it matches the power in the sample beam. In a simple ( flatbed ) system with a chart recorder, the movement of the mechanical attenuator is directly linked to the chart recorder. The output spectrum is essentially a record of the degree of... 

The puzzling behavior of benzene, its unreactivity, and the inference that all six carbon atoms must be linked in the same way could not be described by an open carbon chain (or vertebrate), nor was it satisfactory to write one true "rational" formula for "empirical" C6H6 benzene. Albert Ladenburg s nonplanar prism formula was the best single representation,... 

In the Fe2P-type structure there are four different groups of equipoints. The distribution of P and Fe atoms in different groups of positions is reported. A number of isostructural binary compounds are known. To the same structure, however, ternary or even more complex phases may be related if different atomic species are distributed in the different sites. This structure can be considered as an example of more complex structures built up by linked triangular prisms of Fe atoms. 

The Yb(III) ion in [Yb(acac)3 H2O 0.5CeH6] is seven coordinated and the coordination polyhedron for this complex is identical with the polyhedron found for Yb(l) in the unsolvated complex, i.e. a capped trigonal prism. Like the unsolvated complex, the hemibenzene solvated ones are also linked in pairs by hydrogen bonds. The benzene molecule occupies a centre of S3unmetry in the complex. All intermolecular contacts involving benzene carbon atoms and acac carbons or oxygens are above 3.5 A (84). 

The crystal structure of the faujasite is built up by linking the sodalite cages tetrahedrally through their hexagonal faces forming connecting hexagonal prisms. 

The strong decline of ATS precursor seizures in 2005 is linked to successes in precursor control, which works by preventing the diversion of chemicals into illicit manufacture. If suspicious precursor shipments are actually suspended or stopped, the amount of seizures will obviously go down. For instance, as a part of project PRISM (Precursors Required In Synthetic drug Manufacture), a task force involving several countries and international organizations, the International Narcotics Control... 

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