Octahedron, truncated views

From a geometrical point of view only, this structure could be compared with that of CsCl, with 1 Ca in place of Cs, and the centre of a 6 B octahedron in place of the Cl atom (in the centre of the cell with its axes parallel to the cell axes). Ca is surrounded by 24 B in a regular truncated cube (octahedra and truncated cubes fill space). A number of hexaborides (of Ca, Sr, Ba, Y and several lanthanides and Th, Np, Pu, Am) have been described as pertaining to this structural type. 

Figure 6a shows a diffraction pattern showing the (1 0 0) orientation of the Pd clusters. The good epitaxy is also reflected from the TEM picture (Fig. 6b) that show clusters with a square outline that are all in the same orientation. Figure 6c shows a profile view of such a particle. From these two images it is now possible to reconstruct the actual shape which is a truncated octahedron exhibiting mainly (111) facets and small (1 0 0) truncations on the top and at the edges (Fig. 6d). After coalescence the particles become flatter and they exhibit now a majority of (1 0 0) facets (see Fig. 6e). Very small clusters have a different shape they are truncated half octahedron as shown in Fig. 6f. This different shape has been...

Figure 6 TEM characterization of the structure and morphology of Pd nanoparticles supported on MgO(l 0 0). (a) Electron diffraction pattern (b) top-view micrograph (c) profile view micrograph of an individual particle (d) drawing of the truncated octahedron shape of a Pd particle (e) shape of a large coalesced particle (0 truncated pyramid shape of a small (<7 nm) Pd particle.

Figure 7.20 Perspective view of the structure of a-Agl (a) the body-centred cubic arrangement of iodide ions in the unit cell (b) the anion centred polyhedron, (a truncated octahedron), around the iodide ion at the unit cell centre. [Note that the ions in part (a) are depicted smaller than ionic radii suggest, for clarity]...

O Keefe et al. [31 [ described "polybenzene" which may be viewed as a 3D truncated octahedron lattice in which edges have been replaced by benzene rings. Only one kind of carbon atom forms the entire net. The six- and eight-membered... 

Fig. 4 Ligated linked products from flexible DNA components. (a) A stick cube and (b) a stick truncated octahedron. Each edge of the cube and the truncated octahedron contains two turns of double-helical DNA. The twisting is confined to the central portion of each edge for clarity, but it actually extends from vertex to vertex, (c) Bonomean rings. Scission of any of the three rings shown results in the unlinking of the other two rings. (View this art in color at www.dekker.com.)...

Fig. 3.13 a Complementary [GaNOs] and HSPB tiles with their corresponding edge lengths, b The hydrogen bonding quasi-truncated octahedron viewed perpendicular to HSPB and [GaNOa] tiles respectively [63]... 

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