Black sphere

Figure Bl.8.4. Two of the crystal structures first solved by W L Bragg. On the left is the stnicture of zincblende, ZnS. Each sulphur atom (large grey spheres) is surrounded by four zinc atoms (small black spheres) at the vertices of a regular tetrahedron, and each zinc atom is surrounded by four sulphur atoms. On the right is tire stnicture of sodium chloride. Each chlorine atom (grey spheres) is sunounded by six sodium atoms (black spheres) at the vertices of a regular octahedron, and each sodium atom is sunounded by six chlorine atoms.

Phosphate release from actin. (a) Monomeric actin with ADP and Pi bound. The protein backbone (tube), ADP (grey spheres), and Ca -Pi (black spheres) are shown. The orientation of the spring indicates the pulling direction during P, unbinding. (b) Force exerted on the deprotonated (solid line) and protonated (dashed line) phosphate during the SMD simulations. 

Fig. 1. Ribbon representation of the three-dimensional structure of D. gigas hydro-genase (32). The large subunit is represented in dark gray. Fe is represented by black spheres, Ni by gray spheres, and inorganic sulfur by white spheres. The C-terminal end of the large subunit is close to the Ni smd completely buried in the structure.

Fig. 14.7 A2EuM See (A=Na, K, Rb, Cs M=Si, Ge) structures. In all structures, the alkali metals are black spheres, Se light spheres, EuSe polyhedra are light grey and M2S06 polyhedra are dark grey.

Fig. 21.21 The oxygen atoms coordination of the two different Ba sites in Ba3BP30- 2 (Ba atoms, black spheres O atoms, grey spheres).

Fig. 1.2 Crystal structures of the major sulfides (metal atoms are shown as smaller or black spheres) (A) galena (PbS) structure (rock salt) (B) sphalerite (ZnS) structure (zinc blende) (C) wurtzite (ZnS) strucmre (D) pyrite structure and the linkage of metal-sulfur octahedra along the c-axis direction in (/) pyrite (FeSa) and (//) marcasite (FeSa) (E) niccolite (NiAs) structure (F) coveUite (CuS) structure (layered). (Adapted from Vaughan DJ (2005) Sulphides. In Selley RC, Robin L, Cocks M, Plimer IR (eds.) Encyclopedia of Geology, MINERALS, Elsevier p 574 (doi 10.1016/B0-12-369396-9/00276-8))...

Here, we have shown an "A" ion (shown as a black sphere) which approaches the surface of "AB" and displaces an "A" ion in this solid phase. A series of "hops", i.e.- from "1" to "7", then occurs in the AB-phase with the final "A" ion ending within the B-phase where a displacement in the normally cubic "B" phase occurs. At the same time, the displaced "B" ion is diffusing in the opposite direction by a series of "hops", i.e.- from "a" to "e" to the interface of "AB" with "A". Note that the "A" phase is shown as a hexagonal phase while "B" is a cubic phase (as is the "AB" phase). It should be clear that the rate of diffusion of "A" will differ firom that of "B". 

Figure 3.19 Schematic representation of surface alloy stability tests. White spheres denote adsorbed hydrogen, black spheres denote solute metal atoms, and gray spheres denote host metal atoms. Adapted from [Greeley and Nprskov, 2007] see this reference for more details.

Fig. 1. Schematic diagram of 12-crown-4 (12-C-4) compared with the analogous core of the metallacrown metal atoms, black spheres C atoms, light gray spheres N atoms medium gray spheres.

Fig. 23 The bonds that constitute crystalline domains must lie nearly parallel to the jy-axis with an angle 6 of less than 20°. Furthermore, the bonds must have at least three neighbors that satisfy 0.7a < Jr + r < 1.3a and ry < r0/2. Note that the crystalline stems deep inside the crystal (black spheres) have six neighbors, while those on the free sin-faces (hatched spheres) have four neighbors. The stems at the half-crystal site, or at the kink site, (white sphere) have three neighbors. Stems attached on the free surface, and those floating in the melt phase have less than three neighbors...

Fig. 27 Shape of crystalline domains at 330 K after 6.4 ns (grey spheres). The crystalline lamellae are found to have rather flat 100 surfaces. Also shown are newly added stems (black spheres) during the next 0.128 ns of simulation. The addition of the stems starts preferentially at kink sites... 

Figure 11 Packing of the Tel62 anions in the crystal structure of [C6H5NH (CH3)2]2 2 io- Black spheres Te white spheres I dashed lines / T contacts...

Fig. 23. Schematic representation of the group IV donor-hydrogen complex with hydrogen in AB site. The black spheres represent the group V atoms (As), the large white ones the group III atoms (Ga), the small white one the hydrogen atom and the dotted sphere the impurity. The lone pair on the threefold coordinated group V atom is not represented.

Fig. 27. Schematic representation of the group III vacancy having one of its dangling bonds saturated by hydrogen. The black spheres represent the group V atoms and the white one the hydrogen atom. 

Figure 7. Traces of the a-carbon polypeptide backbone of domains 1 and 6 in the hCP structure. Domain 1 is shown (shaded) on the left hand side of the diagram this domain contributes four histidine residues (not shown) to the trinuclear cluster copper atoms are depicted as black spheres. Domain 6 is on the right hand side of the figure and also contributes four histidine residues to the cluster. The portion of the polypeptide chain colored black is that which is missing in the truncated enzyme. This polypeptide, residues 991 to 1046 inclusive, includes two histidine residues bound to the trinuclear copper center and three residues bound to the mononuclear copper in domain 6 these residues are depicted in black. The absence of the C-terminal polypeptide would also remove over 50% of the interdomain hydrogen-bond and iron-pair interactions observed in the intact enzyme.

Fig-1 View of the pentanuclear assembly of [Fe2(totrz)5(NCS)4]2[Fe(totrz)2(NCS)2(H20)2] (p-tolyl groups and hydrogen atoms of the triazole have been omitted for clarity). Shining black, white, and black and white small spheres correspond to nitrogen, carbon and sulfur atoms, respectively. The larger black spheres correspond to iron(II) ions... 

Figure 15 Sketch of the local environment along a polybutadiene chain of cis-and trans-conformers. For sp3-hybridized carbon atoms (indicated by the gray spheres), the chemical shift is different when they belong to a cis-monomer than when they belong to a trans-monomer. For sp2-hybridized carbon atoms (shown by black spheres) in a cis-monomer, NMR shows a different chemical shift whether they have another cis-monomer as a neighbor or a trans-monomer as a neighbor, and it is similar for the sp2-hybridized carbon atoms in the trans monomer.

Fig. 3.6-9. Representation of the cluster core of [C PSiBuhk 31. The black spheres (Cu atoms) form a cuboctahedron, the grey spheres (P atoms) an octahedron. The white spheres...

Fig. 16.5 (a) Supercell models for bulk anatase (96 atoms) and (b) partial geometry model for three carbon impurities in the anatase supercell. The yellow spheres represent 0 atoms, the small brown spheres represent Ti atoms, and the black spheres represent the carbon impurities. Adapted from Pacchioni etal. [76] with kind permission from the American Chemical Society (2005). 

Figure 3.10 Schematic representation of all the critical points in the dimeric structure (BH3-NH3)2. The hydrogen atoms are represented by the small gray spheres, and the bond critical points are represented by the small black spheres. The ring critical points are noted as two large spheres. A dotted line shows the dihydrogen bond s bond path. (Reproduced with permission from ref. 16.)...

Figure 6.1 Stationary structure of dimer (LiH-H20)2 with short H- H distances obtained by calculations at the MP2/6-31-r-rG(d,p) level. The black spheres represent the Li atoms and the largest spheres are the O atoms.

Fig. L Schematic representation showing two layers of 11A tobermorite adapted from Ziegler (2000) after Hamid (1981). The tetrahedra represent Si04 units, the grey and black spheres represent Ca atoms in the interlayers and main layers respectively and the open circles represent H20 molecules.

Can the creature understand you The two black spheres just stare at both you and the photos and then, suddenly, hundreds of moist, baseball-sized flesh-balls come near you and you feel as if you re being pushed down. There is a deep roaring sound. Is this what Lucifer felt as he was expelled from Heaven (Fig. 6.3). 

Fig. 4.8. Functional domains, DNA-binding and HRE structure of the steroid hormone receptors. a) domain structure of the steroid hormone receptor. AFl, AF2 domains that mediate the stimulation of the transcription, b) schematic representation of the two Zn -Cys4 binding motils of the DNA-binding domains, c) Complex formation between the dimeric DNA-binding domains of the gluccocorticoid receptor and the HRE. The black spheres represent Zn ions. After Luisi et al., 199L d) Consensus sequence and configuration of the HRE elements of the steroid hormone receptor.

Fig. 20. Partial structure of MMo4E8 or MoSX. Black spheres represent or X.

Schematic illustration of the icosahedral rhinovirus 14. (a) Shown is the icosahedron comprised of 60 copies each of VP1 (light gray), VP2 (black), and VP3 (gray). The shaded circles around each five-fold axis indicate the canyon positions. Also indicated is the approximate position of the VP1 hydrophobic pocket that lies underneath the surface of the virion, (b) An icosahedral pentamer is expanded with one viral protomer shown as a protein ribbon diagram, (c) This pentamer is seen in a cutaway view. Here VP1 is white, VP2 and VP4 black, and VP3 gray. A capsid-binding compound is depicted as black spheres inside the VP1 ribbon diagram. The cross hatched regions on the (c) schematic (right) indicate areas that disorder when HRV14 crystals are exposed to acid.

Figure 2.2 Structure of crystalline [Lii4(O)(N(H)(C5Hc,))i2] highlighting the central Lii4Ni2C> metal-heteroatom unit in bold lines. Lithium atoms are shown as large black spheres, and nitrogen atoms are shown as small black spheres, the central oxygen atom and thecarbon atoms are white spheres. Selected bond lengths Lil-OI 1.888(10) A, Lil-NI 2.080 (5)A, Li2-N1 2.062(8) A, Li3-N1 2.002(8) A...

Figure 2.6 Illustration of the macrocyclic ring structure in [(tmp , a,iMg2 Cf,Hi(Cff t) ] showing guest dideprotonated toluene ligand. Sodium and magnesium atoms are shown as large black spheres, nitrogen atoms as small black spheres and carbon atoms as white spheres. Selected bond lengths Nal-N2 2.626(2)A, Nal-N3 2.393(2) A, Na1-C28 2.691(2)A, Na2-N3 2.350(2)A, Na2-NI0 2.596(2)A, Na2-C28 2.682(2)A, Mg1-N1 2.048(2)A, Mg1-N2 2.051(2) A, Mg1-C28 2.200(2)...

Figure 3.1 Illustration of the linear coordination geometry in the monomeric complex [(Cf,HiMes2-2,6)Be N(SiMe ,)2/]. The beryllium, nitrogen and silicon atoms are shown as black spheres and carbon atoms are white...

Figure 3.3 Representation of the linear complex [MglN(r ipp)(SiMc-,)hl with magnesium and nitrogen atoms shown as black spheres and carbon atoms are white. Mg Nl bond length 1.919(2) A...

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