K9Y3[Si12O32]F2

• Main Authors: Volker Kahlenberg, Tanja Manninger
• Format: Article
• Language: English
• Published: International Union of Crystallography 2014-02-01
• Series: Acta Crystallographica Section E
• Online Access: http://scripts.iucr.org/cgi-bin/paper?S1600536814001470

Single-crystals of the title compound, nonapotassium triyttrium dodecasilicate difluoride, were obtained from flux synthesis experiments in the system SiO2—Y2O3—KF. The crystal structure belongs to the group of single-layer silicates and is based on silicate sheets parallel to (110). A single layer contains secondary (Q2) and tertiary (Q3) silicate tetrahedra in the ratio 1:2 and is build up from six-, eight- and twelve-membered rings. The linkage between neighboring layers is achieved by two crystallographically independent Y3+ cations, which are coordinated by six oxygen ligands in form of distorted octahedra. Charge compensation is accomplished by incorporation of additional F− anions and K+ cations in the structural channels, forming anion-centred [F2K7] groups. Apart from one K+ and one Y3+ cation (each with site symmetry -1), the 30 crystallographically independent atoms reside on general positions.