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aDepartment of Chemsitry and Biochemistry, University of Arizona, 1306 E. University Blvd., Tucson, Arizona 85721-0041, USA, and bDepartment of Geosciences, University of Arizona, 1040 E. 4th Street, Tucson, Arizona 85721-0077, USA
Correspondence e-mail: ywyang@email.arizona.edu
Lotharmeyerite, calcium bis(zinc/manganese) bis(arsenate) bis(hydroxide/hydrate), Ca(Zn,Mn3+)2(AsO4)2(H2O,OH)2, is a member of the natrochalcite group of minerals, which are characterized by the general formula AM2(XO4)2(H2O,OH)2, where A may be occupied by Pb2+, Ca2+, Na+, and Bi3+, M by Fe3+, Mn3+, Cu2+, Zn2+, Co2+, Ni2+, Al3+, and Mg2+, and X by PV, AsV, VV, and SVI. The minerals in the group display either monoclinic or triclinic symmetry, depending on the ordering of chemical components in the M site. Based on single-crystal X-ray diffraction data of a sample from the type locality, Mapimi, Durango, Mexico, this study presents the first structure determination of lotharmeyerite. Lotharmeyerite is isostructural with natrochalcite and tsumcorite. The structure is composed of rutile-type chains of edge-shared MO6 octahedra (site symmetry
) extending along [010], which are interconnected by XO4 tetrahedra (site symmetry 2) and hydrogen bonds to form [M2(XO4)2(OH,H2O)2] sheets parallel to (001). These sheets are linked by the larger A cations (site symmetry 2/m), as well as by hydrogen bonds. Bond-valence sums for the M cation, calculated with the parameters for Mn3+ and Mn2+ are 2.72 and 2.94 v.u., respectively, consistent with the occupation of the M site by Mn3+. Two distinct hydrogen bonds are present, one with O
O = 2.610 (4) Å and the other O
O = 2.595 (3) Å. One of the H-atom positions is disordered over two sites with 50% occupancy, in agreement with observations for other natrochalcite-type minerals, such as natrochalcite and tsumcorite.
For lotharmeyerite, see: Dunn (1983
); Kampf et al. (1984
); Brugger et al. (2002
). For related minerals in the natrochalcite group, see: Tillmanns & Gebert (1973
); Chevrier et al. (1993
); Ansell et al. (1992
); Krause et al. (1998
, 1999
, 2001
); Brugger et al. (2000
, 2002
). Parameters for bond-valence calculations were taken from Brese & O'Keeffe (1991
). For additional information on related minerals, see: Ferraris & Ivaldi (1984
); Krickl & Wildner (2007
).
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Data collection: APEX2 (Bruker, 2004
); cell refinement: SAINT (Bruker, 2004
); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008
); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008
); molecular graphics: XtalDraw (Downs & Hall-Wallace, 2003
); software used to prepare material for publication: publCIF (Westrip, 2010
).
Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: PK2375 ).
The authors gratefully acknowledge support of this study by the Arizona Science Foundation.
Ansell, G. H., Roberts, A. C., Dunn, P. J., Birch, W. D., Ansell, V. E. & Grice, J. D. (1992). Can. Mineral. 30, 225-227. ![[ChemPort]](../../../../../../logos/chemportborder.gif)
Brese, N. E. & O'Keeffe, M. (1991). Acta Cryst. B47, 192-197.
![[details]](../../../../../../b/graphics/details.gif)
Brugger, J., Krivovichev, S. V., Kolitsch, U., Meisser, N., Andrut, M., Ansermet, S. & Burns, P. C. (2002). Can. Mineral. 40, 1597-1608.
![[ChemPort]](../../../../../../logos/chemportborder.gif)
Brugger, J., Meisser, N., Schenk, K., Berlepsch, P., Bonin, M., Armbruster, T., Nyfeler, D. & Schmidt, S. (2000). Am. Mineral. 85, 1307-1314. ![[ChemPort]](../../../../../../logos/chemportborder.gif)
Bruker (2004). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA.
Chevrier, G., Giester, G. & Zemann, J. (1993). Z. Kristallogr. 206, 7-14.
![[ChemPort]](../../../../../../logos/chemportborder.gif)
Downs, R. T. & Hall-Wallace, M. (2003). Am. Mineral. 88, 247-250. ![[ChemPort]](../../../../../../logos/chemportborder.gif)
Dunn, P. J. (1983). Mineral. Rec, 14, 35-36. ![[ChemPort]](../../../../../../logos/chemportborder.gif)
Ferraris, G. & Ivaldi, G. (1984). Acta Cryst. B40, 1-6.
![[details]](../../../../../../b/graphics/details.gif)
Kampf, A. R., Shigley, J. E. & Rossman, G. R. (1984). Mineral. Rec, 15, 223-226. ![[ChemPort]](../../../../../../logos/chemportborder.gif)
Krause, W., Belendorff, K., Bernhardt, H. J., McCammon, C. A., Effenberger, H. & Mikenda, W. (1998). Eur. J. Mineral. 10, 179-206. ![[ChemPort]](../../../../../../logos/chemportborder.gif)
Krause, W., Bernhardt, H. J., Effenberger, H. & Martin, M. (2001). Neues Jahr. Mineral. Monatsh. 2001, 558-576.
Krause, W., Effenberger, H., Bernhardt, H. J. & Martin, M. (1999). Neues Jahr. Mineral. Monatsh. 1999, 505-517.
Krickl, R. & Wildner, M. (2007). Eur. J. Mineral. 19, 805-816. ![[ChemPort]](../../../../../../logos/chemportborder.gif)
Parkin, S., Moezzi, B. & Hope, H. (1995). J. Appl. Cryst. 28, 53-56.
![[details]](../../../../../../j/graphics/details.gif)
Sheldrick, G. M. (2005). SADABS. University of Göttingen, Germany.
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.
![[details]](../../../../../../a/graphics/details.gif)
Tillmanns, E. & Gebert, W. (1973). Acta Cryst. B29, 2789-2794.
![[ISI]](../../../../../../logos/isiborder.gif)
Westrip, S. P. (2010). J. Appl. Cryst. 43, 920-925.
![[details]](../../../../../../j/graphics/details.gif)