Structure of magnesium selenate enneahydrate, MgSeO4·9H2O, from 5 to 250K using neutron time-of-flight Laue diffraction
| Autor: | Dario Alfè, Andrew Dominic Fortes, Matthias J. Gutmann, Eduardo R. Hernández |
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| Přispěvatelé: | Fortes, A. Dominic, Alfè, Dario, Hernández, Eduardo R., Gutmann, Matthias J., Science and Technology Facilities Council (UK), Ministerio de Ciencia e Innovación (España) |
| Jazyk: | angličtina |
| Rok vydání: | 2015 |
| Předmět: |
Materials Chemistry2506 Metals and Alloys
Magnesium selenate enneahydrate Atomic and Molecular Physics and Optic Neutron diffraction 02 engineering and technology Crystal structure Dodecamer 010402 general chemistry 01 natural sciences symbols.namesake neutron diffraction Ab initio quantum chemistry methods Materials Chemistry magnesium selenate enneahydrate Chemistry Electronic Optical and Magnetic Material Metals and Alloys technology industry and agriculture Space group 021001 nanoscience & nanotechnology Research Papers Atomic and Molecular Physics and Optics 0104 chemical sciences Electronic Optical and Magnetic Materials Crystallography X-ray crystallography biological sciences symbols 0210 nano-technology Raman spectroscopy dodecamer Powder diffraction Monoclinic crystal system |
| Zdroj: | Digital.CSIC. Repositorio Institucional del CSIC instname Acta Crystallographica Section B, Structural Science, Crystal Engineering and Materials |
| Popis: | The complete structure of MgSeO4·9H2O has been refined from neutron single-crystal diffraction data obtained at 5, 100, 175 and 250 K. It is monoclinic, space group P21/c, Z = 4, with unit-cell parameters a = 7.222 (2), b = 10.484 (3), c = 17.327 (4) Å, [beta] = 109.57 (2)°, and V = 1236.1 (6) Å3 [[rho]calc = 1770 (1) kg m-3] at 5 K. The structure consists of isolated [Mg(H2O)6]2+ octahedra, [SeO4]2- tetrahedra and three interstitial lattice water molecules, all on sites of symmetry 1. The positions of the H atoms agree well with those inferred on the basis of geometrical considerations in the prior X-ray powder diffraction structure determination: no evidence of orientational disorder of the water molecules is apparent in the temperature range studied. Six of the nine water molecules are hydrogen bonded to one another to form a unique centrosymmetric dodecamer, (H2O)12. Raman spectra have been acquired in the range 170-4000 cm-1 at 259 and 78 K; ab initio calculations, using density functional theory, have been carried out in order to aid in the analysis of the Raman spectrum as well as providing additional insights into the geometry and thermodynamics of the hydrogen bonds. Complementary information concerning the thermal expansion, crystal morphology and the solubility are also presented. A. D. Fortes acknowledges financial support from the Science and Technology Facilities Council, grant numbers PP/E006515/1 and ST/K000934/1 and thanks Dr Andy Beard (Birkbeck, University of London) for assistance with the microprobe measurements. E. R. Hernández acknowledges support from the Spanish Research and Innovation Office through project No. FIS2012-31713. |
| Databáze: | OpenAIRE |
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