K2.9Rb0.1ErSi3O9: a novel, non-centrosymmetric chain silicate and its crystal structure
- Author(s)
- Maria Wierzbicka-Wieczorek, Uwe Kolitsch, Lutz Nasdala, Ekkehart Tillmanns
- Abstract
The new, non-centrosymmetric chain silicate, K2.9Rb0.1ErSi3O9, was prepared by a high-temperature flux-growth technique, and its crystal structure was determined from single-crystal X-ray intensity data (Mo-Ka, 293 K) in space P1, with a = 6.672(1), b = 6.719(1), c = 6.725(1) Å, a = 108.87(3), ß = 106.72(3), ? = 107.61(3)°, V = 245.82(6) Å3, Z = 1, R(F) = 2.81%. The compound represents a novel structure type. K2.9Rb0.1ErSi3O9 is characterized by a mixed octahedral-tetrahedral framework, in which each corner of the isolated ErO6 octahedron ( = 2.26 Å) is linked to infinite [Si3O9] chains extending approximately along [111]. This connectivity results in a microporous character with two different, narrow channels that extend parallel to [111] and [100] and host K+ cations. The atomic arrangement is strongly pseudorhombohedral. A single-crystal Raman spectrum of K2.9Rb0.1ErSi3O9 is in agreement with the low space-group symmetry. Relations to minerals and synthetic compounds based on [Si3O9] chains are discussed, revealing that the geometry of the chain in K2.9Rb0.1ErSi3O9 is similar to that in pectolite, NaCa2[HSi3O9].
- Organisation(s)
- Department of Mineralogy and Crystallography
- Journal
- Mineralogical Magazine
- Volume
- 74
- Pages
- 979-990
- No. of pages
- 12
- ISSN
- 0026-461X
- DOI
- https://doi.org/10.1180/minmag.2010.074.6.979
- Publication date
- 2010
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 1051 Geology, Mineralogy
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/a26407d9-28d1-4fe8-a778-f9c3d74c3f87