Quick Search:    advanced search

GSW Home   GeoRef Home   My GSW Alerts   Contact GSW   About GSW   Journals List   Help

This Article Figures Only Full Text Full Text (PDF) Supplementary Data Info Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Ma, H. Articles by Chipera, S. J. Search for Related Content GeoRef GeoRef Citation

Determination of the crystal structure of sanderite, MgSO₄·2H₂O, by X-ray powder diffraction and the charge flipping method

¹ Department of Geological Sciences, Indiana University, 1001 East 10^th Street, Bloomington, Indiana 47405, U.S.A.
² Chesapeake Energy Corporation, 6100 N. Western Avenue, Oklahoma City, Oklahoma 73118, U.S.A.

Correspondence: ^* E-mail: hongma{at}indiana.edu

The crystal structure of sanderite, MgSO₄·2H₂O, was determined from laboratory X-ray powder diffraction data measured from 2–140 °2 using CuK radiation. Sanderite is orthorhombic, space group P2₁2₁2₁, with unit-cell parameters a = 8.8932(1) Å, b = 8.4881(1) Å, c = 12.4401(2) Å, V = 939.16(3) ų, Z = 8. The crystal structure model was determined using the charge flipping method and was refined using fundamental parameters Rietveld refinement method to R_wp = 6.52%, R_exp = 1.89%, and ² = 3.43. Bond-valence calculations for the refined model show that the structure is chemically reasonable. In the refined structure, Mg²⁺ cations are coordinated by four O atoms from [SO₄]^2– groups tetrahedra and by two H₂O molecules, forming distorted octahedra. By sharing vertex O atoms, [SO₄] and [MgO₄(H₂O)₂] octahedra build up a 3-D framework.

Key Words: Sanderite • MgSO₄·2H₂O • crystal structure • charge flipping • structure determination • powder diffraction

This article has been cited by other articles:

				H. Ma, D. L. Bish, H.-W. Wang, and S. J. Chipera Structure determination of the 2.5 hydrate MgSO4 phase by simulated annealing American Mineralogist, July 1, 2009; 94(7): 1071 - 1074. [Abstract] [Full Text] [PDF]