Isotropic lazurite: A cubic single crystal with an incommensurate three-dimensional modulation of the structure
- Russian Academy of Sciences, Shubnikov Institute of Crystallography (Russian Federation), E-mail: bolotina@ns.crys.ras.ru
The incommensurately modulated structure of the isotropic lazurite Na{sub 6.41}Ca{sub 1.36}K{sub 0.04}(Si{sub 6.09}Al{sub 5.91})O{sub 24}(SO{sub 4}){sub 1.73}Cl{sub 0.1}= {sub 7} from the Baikal region is solved in the (3 + 3)-dimensional symmetry group P23({gamma}{gamma}0) [where {gamma} = 0.2154(1)] with the basic unit cell parameter a = 9.077(1) A. The structure is refined to R{sub 0} = 0.04 for the main reflections and R{sub 1} = 0.15 for the satellite reflections. Six modulation waves are directed along the side diagonals of the unit cell. The structural model under investigation is compared with the twin model previously proposed for the same crystal. The structural data obtained are used to construct fragments of the modulated structure. Considering the constructed fragments of the modulated structure, it has become possible for the first time to reproduce and describe the three-dimensional modulation of the framework and to reveal its relation to modulations of intraframework atoms.
- OSTI ID:
- 21091429
- Journal Information:
- Crystallography Reports, Vol. 51, Issue 6; Other Information: DOI: 10.1134/S106377450606006X; Copyright (c) 2006 Nauka/Interperiodica; Article Copyright (c) 2006 Pleiades Publishing, Inc; Country of input: International Atomic Energy Agency (IAEA); ISSN 1063-7745
- Country of Publication:
- United States
- Language:
- English
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