Crystallography

X-ray study of the alkali metals at low temperatures

Cold working of sodium metal converts body centred sodium metal to a mixture of a hexagonal form and body centred sodium at 5 K. The hexagonal from converts back to the body-centred form at 100-100 K.

Cold working of lithium metal converts body centred lithium metal to a mixture of a hexagonal form and body centred lithium at 78 K.

Potassium, rubidium, and caesium retain their body centred structure after cooling

X-ray study of the alkali metals at low temperatures, Barrett, C. S. , Acta Crystallographica, 08/1956, Volume 9, Issue 8, p.671 - 677, (1956)

Crystallographic Data. 177. Uranium Mononitride

Crystal structure of uranium nitride, UN. The structure is face-centered cubic with a lattice constant of 4889 ± 0.001 Å at 26°C and sodium chloride type. The theoretical density is 14315 kg m–3, and the U—N bond distance for coordination number 6 is 2.4449 Å.

Crystallographic Data. 177. Uranium Mononitride, Kempter, Charles, McGuire Joseph, and Nadler M. , Analytical Chemistry, 01/1959, Volume 31, Issue 1, p.156 - 157, (1959)

Die Kristallstrukturen von ScCl3, TiCl3 und VCl3

ScCl3, TiCl3 und VCl3 kristallisieren hexagonal-rhomboedrisch in dem gleichen Gitter wie FeCl3 (DO5-Typ).

Die Kristallstrukturen von ScCl3, TiCl3 und VCl3, Klemm, Wilhelm, and Krose Ehrhard , Zeitschrift für anorganische Chemie, 05/1947, Volume 253, Issue 3-4, p.218 - 225, (1947)

Tb3N@C84 :  An Improbable, Egg-Shaped Endohedral Fullerene that Violates the Isolated Pentagon Rule

Abstract.The structure of isomer 2 of Tb3N@C84 has been determined through single-crystal X-ray diffraction on Tb3N@C84·NiII(OEP)·2(C6H6). The carbon cage has a distinct egg shape due to the presence of a single pair of fused pentagons at one apex of the molecule. Thus, although 24 IPR structures are available to the C84 cage, Nature utilizes one of the 51 568 isomeric structures that do not conform to the IPR for this unusual molecule. The Tb3N portion of isomer 2 of Tb3N@C84 is strictly planar. One Tb atom is nestled within the fold of the fused pentagons, while the other Tb atoms are disordered over four pairs of sites.

Tb3N@C84 :  An Improbable, Egg-Shaped Endohedral Fullerene that Violates the Isolated Pentagon Rule, Beavers, Christine M., Zuo Tianming, Duchamp James C., Harich Kim, Dorn Harry C., Olmstead Marilyn M., and Balch Alan L. , Journal of the American Chemical Society, 09/2006, Volume 128, Issue 35, p.11352 - 11353, (2006)

BuckyEgg

BuckyEgg

BuckyEgg Tb3N@C84: image credit Mark Winter

Ozone

Ozone

Ozone. Credit Mark Winter

Gypsum

Gypsum

Gypsum, cover from Geology; April 2007; v. 35; no. 4; p. 327-330; DOI: 10.1130/G23393A.11

Polonium metal structure

Polonium metal structure

Polonium metal crystal structure

Polonium dioxide

Polonium dioxide

Polonium dioxide

Polonium dichloride

Polonium dichloride

Polonium dichloride crystal structure

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Copyright 1993-2011 Mark Winter [The University of Sheffield and WebElements Ltd, UK]. All rights reserved.