Crystal structure of pseudojohannite, with a revised formula Cu3(OH)2[(UO2)4O4(SO4)2](H2O)12
| Authors | |
|---|---|
| Year of publication | 2012 |
| Type | Article in Periodical |
| Magazine / Source | American Mineralogist |
| MU Faculty or unit | |
| Citation | |
| Doi | http://dx.doi.org/10.2138/am.2012.4127 |
| Field | Solid matter physics and magnetism |
| Keywords | Pseudojohannite; zippeite group; uranyl sulfate; X ray diffraction; crystal structure; chemical composition |
| Description | The crystal structure of pseudojohannite from White Canyon, Utah, was solved by charge-flipping from single-crystal X-ray diffraction data and refined to an Robs = 0.0347, based on 2664 observed reflections. Pseudojohannite from White Canyon is triclinic, P-1, with a = 8.6744(4), b = 8.8692(4), c = 10.0090(5) A, alpha = 72.105(4)degrees, beta = 70.544(4)degrees, gamma = 76.035(4)degrees, and V = 682.61(5) A^3, with Z = 1 and chemical formula Cu3(OH)2[(UO2)4O4(SO4)2](H2O)12. The crystal structure of pseudojohannite is built up from sheets of zippeite topology that do not contain any OH groups; these sheets are identical to those found in zippeites containing Mg2+, Co2+, and Zn2+. The two Cu2+ sites in pseudojohannite are [5]- and [6]-coordinated by H2O molecules and OH groups. The crystal structure of the pseudojohannite holotype specimen from Jáchymov was refined using Rietveld refinement of high-resolution powder diffraction data. Results indicate that the crystal structures of pseudojohannite from White Canyon and Jáchymov are identical. |
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