Gray band structure

Figure 18-8 Stereoscopic ribbon diagrams of the chicken bc1 complex (A) The native dimer. The molecular twofold axis runs vertically between the two monomers. Quinones, phospholipids, and detergent molecules are not shown for clarity. The presumed membrane bilayer is represented by a gray band. (B) Isolated close-up view of the two conformations of the Rieske protein (top and long helix at right) in contact with cytochrome b (below), with associated heme groups and bound inhibitors, stigmatellin, and antimycin. The isolated heme of cytochrome c, (left, above) is also shown. (C) Structure of the intermembrane (external surface) domains of the chicken bcx complex. This is viewed from within the membrane, with the transmembrane helices truncated at roughly the membrane surface. Ball-and-stick models represent the heme group of cytochrome cy the Rieske iron-sulfur cluster, and the disulfide cysteines of subunit 8. SU, subunit cyt, cytochrome. From Zhang et al.105...

Fig.6. Ribbon drawing of the Cu.ZnSOD monomer (M2SODD183N) showing the secondary structure elements arranged in the Greek-key barrel fold. The metal ions are represented by spheres of arbitrary dimensions (copper, light gray zinc, dark gray) (Band et al., 1998).

Figure 4.7. The LCAO (tight-binding) band structure for ReOs. The dashed line represents the Fermi energy. To the far right is the density-of-states (DOS) curve for states of one spin. The occupied states (up to the Fermi level) are shaded gray. Note that the valence band is completely filled while the conduction band is partially filled. Hence, ReOs should be metallic.

The conductivities of some ceria-containing compounds obtained from the literature have been compiled and shown as solid lines in Fig. 2.12. The main dopants for ceria belong to the alkaline earth or rare-earth metal series and the majority of doped samples exhibit conductivity values which fall into a rather limited band (gray band in Fig. 2.12), which points to a similar behaviour for all doped ceria samples. Exceptions are pure ceria and ceria doped with redox elements like Pr and Tb which give rise to electronic contribution to conductivity. An important requirement is that a homogeneous solid solution forms between the two oxides, which maintains the fluorite structure since the presence of a second phase or phase inhomogeneity due to insufficient solubility can affect ionic conductivity. The very low values of conductivity found for BaO and MgO-doped ceria were in fact attributed to the low solubility of these oxides into the lattice of When the... 

Figure 19 Upper valence and lower conduction band structure of nickel oxide corresponding to different percentages of exact exchange in Becke-Lee-Yang-Parr exchange-correlation functional. Black and gray lines correspond to spin-up and spin-down states, respectively.

Fig. 2.2 Left Formation of the valence and conduction bands in covalent semiconductors liom bonding and antibonding sp orbitals, respectively. Right Calculated electronic band structure of silicon [1]. The gray area indicates occupied states in the valence band of the material...

S. Groves and W. Paul, Band structure of gray tin, Phys. Rev. Letters 11, 194-96... 

Alexander and Gray 70) and Caulton 71) have studied the electronic spectrum of the species [Co(CN)5] . Although direct proof is lacking, it has been affirmed that the optical and E. P. R. spectra are consistent with an essentially square p5u-amidal stereochemistry and are inconsistent with a trigonal bipyramidal structure (70). It has been claimed, however, that this species may be actually six-coordinate in water, i. e. [Co(CN)5(H20)]3- (72). The spectrum of [Co(CN)5]3. has four bands of low intensity between 10 and 32 kK, as well as two high intensity bands at higher frequence (Table 7). 

Figure 2. Photomicrographs showing some of the common entities found in Antarctic coals reflected light, X 150 A—Vitrinoia with cracks. B—Bright inerts in a mixture of vitrinoids (gray) and clays (black), C—Semifusinoids preserving cellular structure. D—Clay minerals (black) containing thin vitrinoid bands (gray)...

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