The keyite crystal structure, revisited
-
Thomas Malcherek
and
Jochen Schlüter
Abstract
The crystal structure of keyite, ideally (Cux,Pb1-x)Cu2Zn4Cd2(AsO4)6 · (H2O)2x, has been refined in space group symmetries C2/c and C1̄. The keyite structure is compared with the alluaudite structure type, confirming that keyite belongs to the alluaudite group of minerals. While keyite is metrically monoclinic, ordering of Cu atoms and associated H2O within one of the channels of the alluaudite heteropolyhedral framework reduces the symmetry to triclinic and gives rise to weak X-ray diffraction maxima forbidden in space group C2/c. Streaks of diffuse scattering parallel b* may indicate additional ordering in layers normal to this direction. Pb2+ partially replaces Cu2+ within the channels, thus also decreasing the concentration of the water ligands coordinating Cu.
References
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Articles in the same Issue
- Inhalt
- Author Index of Volume 228 Issues 1–11
- Symmetry and the polar state of condensed molecular matter
- “Forbidden” reflections in neutron diffraction on bismuth metal oxides: symmetry reduction, λ/2 effect or Umweganregung?
- The keyite crystal structure, revisited
- Liebau density vector: a new approach to characterize lone electron pairs in mullite-type materials
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- Crystal structures of mefloquine-oxazolidine derivatives, 4-[3-(halophenyl)hexahydro[1,3]oxazolo[3,4-a]pyridin-1-yl]- 2,8-bis(trifluoromethyl)quinolines
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Articles in the same Issue
- Inhalt
- Author Index of Volume 228 Issues 1–11
- Symmetry and the polar state of condensed molecular matter
- “Forbidden” reflections in neutron diffraction on bismuth metal oxides: symmetry reduction, λ/2 effect or Umweganregung?
- The keyite crystal structure, revisited
- Liebau density vector: a new approach to characterize lone electron pairs in mullite-type materials
- Magnesium and cadmium in covalently bonded networks: synthesis and structure of AETMg and AETCd (AE = Ca, Sr; T = Pd, Ag, Pt, Au) with TiNiSi type structure and the solid solution Yb2–xPtMgx
- Synthesis and structure of RE2RuMg2 (RE = Dy, Ho, Er, Tm, Lu) – i5 superstructures of the bcc packing
- Co4 clusters in the high-temperature phase La18Co28In3
- Crystal structures of mefloquine-oxazolidine derivatives, 4-[3-(halophenyl)hexahydro[1,3]oxazolo[3,4-a]pyridin-1-yl]- 2,8-bis(trifluoromethyl)quinolines
- X-ray crystal structures of specifically substituted and derived 4,4′-dihydroxybiphenyls. Influence of the structural modification
