If you are experiencing problems downloading PDF or HTML fulltext, our helpdesk recommend clearing your browser cache and trying again. If you need help in clearing your cache, please click here . Still need help? Email help@ingentaconnect.com

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

$14.96 plus tax (Refund Policy)

Buy Article:

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,  = 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 > 4(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 ( = 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) Åand 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 cornerlinked 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: CRYSTAL STRUCTURE; PHOSPHATES; TWINNING; ULRICHITE; URANIUM

Document Type: Research Article

DOI: http://dx.doi.org/10.1180/0026461016560003

Publication date: December 1, 2001

More about this publication?
Related content

Tools

Favourites

Share Content

Access Key

Free Content
Free content
New Content
New content
Open Access Content
Open access content
Subscribed Content
Subscribed content
Free Trial Content
Free trial content
UA-1313315-23
Cookie Policy
X
Cookie Policy
ingentaconnect website makes use of cookies so as to keep track of data that you have filled in. I am Happy with this Find out more