The γ-polymorph of AgZnPO(4) with an ABW zeolite-type framework topology

Acta Crystallogr Sect E Struct Rep Online. 2010 Oct 2;66(Pt 11):i74. doi: 10.1107/S1600536810038717.

Abstract

The γ-polymorph of the title compound, silver zinc orthophos-phate, was synthesized under hydro-thermal conditions. The structure consists of ZnO(4), PO(4) and AgO(4) units. The coord-ination spheres of Zn(II) and P(V) are tetra-hedral, whereas the Ag(I) atom is considerably distorted from a tetra-hedral coordination. Each O atom is linked to each of the three cations. An elliptic eight-membered ring system is formed by corner-sharing of alternating PO(4) and ZnO(4) tetra-hedra, leading to a framework with an ABW-type zeolite structure. The framework encloses channels running parallel to [100] in which the Ag cations are located, with Ag⋯Ag contacts of 3.099 (3) Å. This short distance results from d(10)⋯d(10) inter-actions, which play a substantial role in the crystal packing. The structure of γ-AgZnPO(4) is distinct from the two other polymorphs α-AgZnPO(4) and β-AgZnPO(4), but is isotypic with NaZnPO(4)-ABW, NaCoPO(4)-ABW and NH(4)CoPO(4)-ABW.