Hydration structure of the barite (001)–water interface [electronic resource] : Comparison of x-ray reflectivity with molecular dynamics simulations
- Washington, D.C. : United States. Dept. of Energy. Office of Basic Energy Sciences, 2017.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy
- Physical Description:
- pages 12,236-12,248 : digital, PDF file
- Additional Creators:
- Argonne National Laboratory
United States. Department of Energy. Office of Basic Energy Sciences
United States. Department of Energy. Office of Scientific and Technical Information
- The three-dimensional structure of the barite (001)-water interface was studied using in situ specular and non-specular X-ray reflectivity (XR). Displacements of the barium and sulfate ions in the surface of a barite crystal and the interfacial water structure were defined in the analyses. The largest relaxations (0.13 Å lateral and 0.08 Å vertical) were observed for the barium and sulfate ions in the topmost unit cell layer, which diminished rapidly with depth. The best fit structure identified four distinct adsorbed species, which in comparison with molecular dynamics (MD) simulations, reveals that they are associated with positions of adsorbed water, each of which coordinates one or two surface ions (either barium, sulfate, or both). These water molecules also adsorb in positions consistent with those of bariums and sulfates in the bulk crystal lattice. These results demonstrate the importance of combining high resolution XR with MD simulations to fully describe the atomic structure of the hydrated mineral surface. As a result, the agreement between the results indicates both the uniqueness of the structural model obtained from the XR analysis and the accuracy of the force field used in the simulations.
- Published through SciTech Connect.
Journal of Physical Chemistry. C 121 22 ISSN 1932-7447 AM
Jacquelyn N. Bracco; Sang Soo Lee; Joanne E. Stubbs; Peter J. Eng; Frank Heberling; Paul Fenter; Andrew G. Stack.
- Funding Information:
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