A novel In3O16 fragment in Cs3In3(PO4)(4)

作者：Zatovsky Igor V^*; Baumer Vyacheslav N; Strutynska Nataliya Yu; Slobodyanik Nikolay S; Shishkin Oleg V

来源：Acta Crystallographica Section C-Crystal Structure Communications, 2010, 66: I71-I74.

DOI：10.1107/S0108270110017695

The double phosphate Cs3In3(PO4)(4), prepared by a flux technique, features a fragment of composition In3O16 formed by three corner-sharing InO6 polyhedra. The central In atom resides on a twofold rotation axis, while the other two In atoms are on general positions. The O atoms in this fragment also belong to PO4 tetrahedra, which link the structure into an overall three-dimensional anionic In-O-P network that is penetrated by tunnels running along c. Two independent Cs+ cations reside inside the tunnels, one of which sits on a centre of inversion. In general, the organization of the framework is similar to that of K3In3(PO4)(4), which also contains an In3O16 fragment. However, in the latter case the unit consists of one InO7 polyhedron and one InO6 polyhedron sharing an edge, with a third InO6 octahedron connected via a shared corner. Calculations of the Voronoi-Dirichlet polyhedra of the alkali metals give coordination schemes for Cs of [9+2] and [8+4] ((1) over bar symmetry), and for K of [8+1], [7+2] and [7+2]. This structural analysis shows that the coordination requirements of the alkali metals residing inside the tunnels cause the difference in the In3O16 geometry.

• 出版日期2010-7