Hostname: page-component-7479d7b7d-68ccn Total loading time: 0 Render date: 2024-07-08T19:04:21.292Z Has data issue: false hasContentIssue false
  • English
  • Français

Revision of the crystal structure of ulrichite, CaCu2+(UO2)(PO4)2·4H2O

Published online by Cambridge University Press:  05 July 2018

U. Kolitsch  and
G. Giester
U. Kolitsch*
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien, Geozentrum, Althanstr. 14, A-1090 Wien, Austria
G. Giester
Affiliation:
Institut für Mineralogie und Kristallographie, Universität Wien, Geozentrum, Althanstr. 14, A-1090 Wien, Austria
*
*E-mail: uwe.kolitsch@univie.ac.at
Get access Rights & Permissions [Opens in a new window]

Abstract

The crystal structure of ulrichite, CaCu2+(UO2)(PO4)2·4H2O (space group P21/c, a = 12.784(3), b = 6.996(1), c = 13.007(3)Å, β = 91.92(1)°, V = 1162.7(4)Å3, Z = 4) was redetermined using X-ray diffraction data measured from a twinned crystal with Mo-Kα radiation and a CCD area detector (2510 unique reflections with Fo > 4σ(Fo), R1 = 8.8%). Ulrichite crystallizes in space group P21/c rather than C2/m reported previously. The newly determined atomic positions give reasonable coordination polyhedra. One unique Ca atom is irregularly coordinated by eight O atoms (<Ca–O> = 2.46 Å). One unique U atom shows a {2+5} coordination with characteristic bond angles and lengths (1.806(11)Å, 1.842(12)Å and five bonds between 2.252(15) and 2.441(11)Å). Furthermore, the structure contains groups in which strongly elongated CuO6 ‘octahedra’ (also describable as CuO4 squares) are corner-linked to two PO4 tetrahedra via two opposite, equatorial O atoms. Edge- and corner-sharing UO7, CaO8 and PO4 polyhedra form heteropolyhedral sheets parallel to (001) that are linked to adjacent sheets via the CuO6 ‘octahedra’ and hydrogen bonds.

Keywords

ulrichitecrystal structuretwinninguraniumphosphates
Type
Research Article
Information
Mineralogical Magazine , Volume 65 , Issue 6 , December 2001 , pp. 717 - 724
Copyright
Copyright © The Mineralogical Society of Great Britain and Ireland 2001

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Baur, W.H. (1981) Interatomic distance predictions for computer simulation of crystal structures. Pp. 31–52 in: Structure and Bonding in Crystals, Vol. II (O'Keeffe, M. and Navrotsky, A., editors). Academic Press, New York.CrossRefGoogle Scholar
Birch, W.D., Mumme, W.G. and Segnit, E.R. (1988) Ulrichite: a new copper calcium uranium phosphate from Lake Boga, Victoria, Australia. Austral. Mineral., 3, 125–31.Google Scholar
Brese, N.E. and O'Keeffe, M. (1991) Bond-valence parameters for solids. Acta Crystallogr., B47, 192–7.CrossRefGoogle Scholar
Brown, I.D. (1996) VALENCE: a program for calculating bond valences. J. Appl. Crystallogr., 29, 479–80.CrossRefGoogle Scholar
Brown, I.D. and Altermatt, D. (1985) Bond-valence parameters obtained from a systematic analysis of the inorganic crystal structure database. Acta Crystallogr., B41, 244–7.CrossRefGoogle Scholar
Burns, P.C., Miller, M.L. and Ewing, R.C. (1996) U6+ minerals and inorganic phases: A comparison and hierarchy of crystal structures. Canad. Mineral., 34, 845–80.Google Scholar
Burns, P.C., Ewing, R.C. and Hawthorne, F.C. (1997) The crystal chemistry of hexavalent uranium: polyhedron geometries, bond-valence parameters, and polymerization of polyhedra. Canad. Mineral., 35, 1551–70.Google Scholar
Eby, R.K. and Hawthorne, F.C. (1993) Structural relationships in copper oxysalt minerals. I. Structural hierarchy. Acta Crystallogr., B49, 28–56.CrossRefGoogle Scholar
Hawthorne, F.C. (1998) Structure and chemistry of phosphate minerals. Mineral. Mag. 62, 141–64.CrossRefGoogle Scholar
Henry, D.A. and Birch, W.D. (1988) Sampleite and associated minerals from the Lake Boga granite quarry, Victoria, Australia. Austral. Mineral., 3, 135–48.Google Scholar
Herbst-Irmer, R. and Sheldrick, G.M. (1998) Refinement of twinned structures with SHELXL97. Acta Crystallogr., B54, 443–9.CrossRefGoogle Scholar
Lambert, U. (1988) Kristallchemie von Cu(I) und Cu(II) in oxidischer Bindung. Heidelberger Geowissen-schaftliche Abhandlungen, 18, 222 pp. (in German).Google Scholar
Li, Y., Krivovichev, S.V. and Burns, P.C. (2001) The crystal structure of Na4(UO2)(CO3)3 and its relationship to schröckingerite. Mineral. Mag. 65, 297–304.CrossRefGoogle Scholar
Shape Software (1999) ATOMS for Windows and Macintosh V5.0.4. Kingsport, TN 37663, USA.Google Scholar
Sheldrick, G.M. (1997a) SHELXS-97, a program for the solution of crystal structur es. Universi ty of Göttingen, Germany.Google Scholar
Sheldrick, G.M. (1997b) SHELXL-97, a program for crystal structure refinement. University of Göttingen, Germany.Google Scholar