The crystal structures of germanate micas, KMg2.5Ge4O10F2 and KLiMg2Ge4O10F2
Abstract
The crystals of KMg2.5Ge4010F2 and KLiMg2Ge4O10F2 were synthesized from mixtures of KF, MgF2, MgO and Ge02, and of KF, LiF, MgO and Ge02, respectively. They have structures of the 1M type mica with cell dimensions of a = 5.421(2), b = 9.353(4), c= 10.533(2)Å and β= 100.14(4)° in KMg2.5Ge4O10F2 and a= 5.395(1), b=9.341(2), c = 10.547(1) Å and β = 99.87(2)° in KLiMg2Ge4O10F2. The structures were refined with full-matrix least-squares procedures (R = 0.055; 1413 hkl; KMg2.5Ge4O10F2 and R = 0.038; 1451 hkl; KLiMg2Ge4O10F2). The non-bridging Ge—O distance is 1.702 Å in the former and 1.704 Å in the latter crystals, whereas the mean bridging Ge—O distances are 1.757 Å in both crystals. In KMg2.5Ge4O10F2, the Mg2+ ions are distributed over the two independent octahedral sites with different populations, and the structure corresponds to that of dioctahedral micas. In KLiMg2Ge4O10F2, the Li+ and Mg2+ ions are distributed practically at random. The ditrigonal distortions of the tetrahedral layers are much larger than those of the corresponding silicates owing to the larger size of GeO4 tetrahedra having the tetrahedral rotation angles of 12.9° and 13.5° in KMg2.5Ge4O10F2 and KLiMg2Ge4O10F2, respectively.
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- Condensed models of structures based on loose packings*
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- Some properties of alkaline earth chalcides and heavy metal halides
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- Partial information about structures with the aid of convolutions
- The crystal structures of germanate micas, KMg2.5Ge4O10F2 and KLiMg2Ge4O10F2
- Optical microscopic examination of orthorhombic Na2SO4 (III) in relation to its transformation to Na2SO4(I) hexagonal*
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- Zur Kristallstruktur von Natriumnitrat
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- X-ray powder data and crystallographic data of copper-salicylaldehyde-s-methylthiosemicarbazone and copper-8-quinolinealdehyde-s-methyltliiosemicarbazone complexes
- An X-ray study of cadmium bromate dihydrate
- Crystal data for 4-4′-tetramethyl-diamino-azobenzene
- An X-ray study of 2-mercapto benzimidazole
- Crystallographic data for the mesogenic material cholesteryl methyl carbonate
Articles in the same Issue
- Rules governing the layer organization of inorganic crystal structures *
- Condensed models of structures based on loose packings*
- Crystal data for β naphthyl and some substituted phenyl maleamic acids
- Dipole-dipole van der Waals interaction in alkali halides
- Some properties of alkaline earth chalcides and heavy metal halides
- The crystal structure of dithiobismorpholine (C4H8NOS)2
- Partial information about structures with the aid of convolutions
- The crystal structures of germanate micas, KMg2.5Ge4O10F2 and KLiMg2Ge4O10F2
- Optical microscopic examination of orthorhombic Na2SO4 (III) in relation to its transformation to Na2SO4(I) hexagonal*
- Elastic, thermoelastic, piezoelectric, linear electrooptic, dielectric, and pyroelectric properties of trigonal Ca3(VO4)2 single crystals
- Refinement of the structure of thiourea: A neutron diffraction study at 293 K
- Zur Kristallstruktur von Natriumnitrat
- Types of sphere packings for crystallographic point groups, rod groups and layer groups
- X-ray powder data and crystallographic data of copper-salicylaldehyde-s-methylthiosemicarbazone and copper-8-quinolinealdehyde-s-methyltliiosemicarbazone complexes
- An X-ray study of cadmium bromate dihydrate
- Crystal data for 4-4′-tetramethyl-diamino-azobenzene
- An X-ray study of 2-mercapto benzimidazole
- Crystallographic data for the mesogenic material cholesteryl methyl carbonate
