You are here: Home :: Area NEM :: Chemistry :: Inorganic chemistry

Dmitry Yu. Pushcharovsky, K. Kabalov, Natalia V. Zubkova, J. Schneider, A.N. Sapozhnikov

Powder Rietveld refinement of armstrongite, CaZr[Si₆O₁₅]·3H₂O

Crystal data and results of structure refinement using powder X-ray diffraction and Rietveld analysis for armstrongite, CaZr[Si₆O₁₅]·3H₂O, are reported. Experimental data were collected using MoK_α1 radiation over the range 2° - 51.98° 2θ. Armstrongite is monoclinic (space group C2, Z = 4), with a = 14.018(1) Å, b = 14.133(1) Å, c = 7.840(1) Å, β = 109.40(1)°. The crystal structure, reported by Kashaev and Sapozhnikov (1978) has been refined by Rietveld analysis, resulting in Rwp = 2.75. The structure is based on a heterogeneous octahedra-tetrahedra framework (ZrSi₆O₁₅) built by corrugated silicate sheets connected by ZrO₆ octahedra. The seven-fold Ca polyhedron contains 2 H₂O molecules. Two new sites for H₂O molecules on the 2-fold axis in the voids of the zeolite like framework allowed to achieve the complete correspondence between chemical and structural data.

Zeitschrift für Kristallographie, Oldenbourg Wissenschaftsverlag

Print ISSN: 0044-2968
Volume: 215, 12/2000
Pages: 757

Journal homepage (external site)

Show all available items of this journal

 

Area NEM