Acta Cryst. (2008). E64, i30-i31  [ doi:10.1107/S1600536808009719 ]

Disodium zinc bis(sulfate) tetrahydrate (zinc astrakanite) revisited

M. E. Díaz de Vivar, S. Baggio, A. Ibáñez and R. Baggio

Abstract: We present a new low-temperature refinement of disodium zinc bis(sulfate) tetrahydrate {systematic name: poly[tetra--aqua-di--sulfato-zinc(II)disodium(I)]}, [Na₂Zn(SO₄)₂(H₂O)₄]_n or Zn astrakanite, which is an upgrade of previously reported data [Bukin & Nozik (1974). Zh. Strukt. Khim. 15, 712-716]. The compound is part of an isostructural family containing the Mg (the original astrakanite mineral), Co and Ni species. The very regular ZnO(aqua)₄O(sulfate)₂ octahedra lie on centres of symmetry, while the rather distorted NaO(aqua)₂O(sulfate)₄ octahedra appear at general positions, linked into a three-dimensional network by the bridging water molecules and the fully coordinated sulfate groups.

Online 7 May 2008

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