The crystal structures of (NH4)3HGe7O16·nH2O and Li4−xHxGe7O16·nH2O determined from powder diffraction data using synchrotron radiation

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Abstract

The structures of two hydrated microporous germanates (NH4)3HGe7O16 · nH2O and Li4−xHxGe7O16 · nH2O [n = 2.72(3) and 5.61(5), respectively], have been determined in space group P4̄3m, Z = 1, with a = 7.71069(1) Å and 7.71936(1) Å respectively, from Rietveld refinement of powder diffraction patterns collected using synchrotron radiation. The profiles contain 119 and 104 reflections, respectively. The structure of these germanates consists of a three-dimensional framework with charge compensating cations and water molecules occupying the interconnecting channels. The ammonium cations occupy sites near the centre of a 3.3 Å window and form a disordered hydrogen-bonded network with the water molecules. This is presumably responsible for the ionic conductivity observed in this material.

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