Cuprite crystal structure

The crystal structure of CU2O (cuprite) is shown in Fig. 1.52, oxygen... 

Fig. 4. Computer-generated crystal structure models nop row. left to right) Cuprite, zinc-blende, rutile, perovskite. iridymite (second row) Cristobalite. potassium dihydrogen phosphate, diamond, pyrites, arsenic (third rowt Cesium chloride, sodium chloride, wurtzite. copper, niccolite (fourth row) Spinel, graphite, beryllium, carbon dioxide, alpha i uanz. [AT T Bel Laboratories ...

Test measurements were performed on Cuprite, Cu20, for various reasons it has a well-known structure (cubic, space group Pn3m, a = 4.2696, Z = 2) and has been examined by conventional X-ray single crystal diffractometry [5, 6] and by synchrotron radiation in the Tow energy regime [7]. As a consequence of the... 

When the conditions of growth of a crystal are unknown the evidence of its shape should be regarded with reserve. There are, indeed, cases in which the shape of a crystal is inconsistent with clear X-ray evidence on atomic structure- for instance, cuprite Cu20 (Greenwood, 1924 Bragg, 1937 Miers, 1929). Possibly this is due to the presence of impurities during growdh (see p. 54). 

Fig. 59. (a) CU2O oxide grains and (b) later-appearing, faceted CU2O oxide crystals formed on Cu(lll) in 0.1 M NaOH at E = 0.2 V. Insert atomic resolution of hexagonal structure showing the of Cu-Cu distances of (lll)-oriented cuprite [128, 129],... 

White Cd(CN)2 is sparingly soluble in water, except in the presence of CN ions, owing to the formation of soluble anionic complexes. On heating it darkens and decomposes at about 200 °C. Cd(CN)2, like Zn(CN)2, has a cubic anti-cuprite structure. Colorless cadmium thiocyanate is sparingly soluble in water, ethanol, and liquid ammonia. In the solid, Cd + is surrounded by an N2S4 octahedron. Cadmium thiocyanate polymers exhibit highly anisotropic physical properties. Yellow Cd(N3)2 is prepared by mixing solutions of Cd(N03)2 and NaNs. The crystals are orthorhombic and decompose with detonation when heated. Cadmium pseudohalides (see Pseudohalide) may be prepared by metathesis (equation 3). 

Structures based on systems of interpenetrating diamond nets. In the structures we have been describing it is possible to trace a path from any atom in the crystal to any other along bonds of the structure, that is, along C-C bonds in diamond, Si-O-Si bonds in cristobalite, etc. In CU2O (the mineral cuprite) each Cu atom forms two collinear bonds and each 0 atom four tetrahedral bonds, and these atoms are linked together in exactly the same way as the 0 and Si atoms... 

There are two main oxides of copper, CU2O and CuO. Cuprite, CU2O, is cubic with the m3m crystal group. It takes a little effort to imagine the structure. Start with the Si structure (dc) and replace all of the Si atoms with anions. Each anion is now surrounded by four other anions. Place a Cu cation between every pair of anions. Then, where there is no tetrahedron in the dc structure, insert a new filled tetrahedron. We could alternatively have just created the tetrahedra of anions with cations between each one, and then stacked the maximum number (without changing their rotation) into the cube. This structure is difficult to visualize ... 

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