Curtin University Homepage
  • Library
  • Help
    • Admin

    espace - Curtin’s institutional repository

    JavaScript is disabled for your browser. Some features of this site may not work without it.
    View Item 
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item
    • espace Home
    • espace
    • Curtin Research Publications
    • View Item

    Computer modelling of the energies and vibrational properties of hydroxyl groups in a- and B-Mg2SiO4

    Access Status
    Fulltext not available
    Authors
    Walker, A.
    Demouchy, S.
    Wright, Kathleen
    Date
    2006
    Type
    Journal Article
    
    Metadata
    Show full item record
    Citation
    Walker, Andrew and Demouchy, Sylvie and Wright, Kathleen. 2006. Computer modelling of the energies and vibrational properties of hydroxyl groups in a- and B-Mg2SiO4. European Journal of Mineralogy 18: 529-543.
    Source Title
    European Journal of Mineralogy
    Additional URLs
    http://www.schweizerbart.de/journals/ejm/
    Faculty
    Department of Applied Chemistry
    Division of Engineering, Science and Computing
    Faculty of Science
    Remarks

    Due to Publisher restrictions the full text is not available.

    URI
    http://hdl.handle.net/20.500.11937/6478
    Collection
    • Curtin Research Publications
    Abstract

    The structure, formation energies and infrared (IR) active vibrational modes of hydrous defects in the iron free end members of two of the most important minerals of the Earth's mantle, a- and B-Mg2SiO4, are studied by atomic-scale computational modelling in order to identify the hydrogen incorporation mechanism observed in experiment. Two computational methods are used; calculations based on inter-atomic potentials provide information on all defect configuration in the two minerals, and a combined quantum mechanical/molecular mechanics embedded cluster method is used to validate selected results. For forsterite (B-Mg2SiO4), the results suggest that IR bands at low frequencies (wavenumbers 3000-3250 cm-1) are related to protons populating M1 vacancies. Despite the unfavourable creation of silicon vacancies, calculated medium- and high-frequency IR bands are linked to protons occupying vacant Si sites. For iron-freewadsleyite (B-Mg2SiO4) IR frequencies for hydrated cation vacancies have been calculated for the first time. The main doublet at 3360-3326 cm-1 is attributed to two OH groups located in a vacant M3 site. IR bands at higher wavenumber such as the anisotropic doublet at 3615-3580 cm-1 appear to be linked to OH in vacant Si sites. Low accuracy on the calculated frequencies does not permit a strict and rigorous assignment of each individual IR band observed in hydrous forsterite and wadsleyite. However, it does allow the identification of the most favourable site for protonation and provides a useful approximation to the corresponding IR stretching frequencies for a given hydrogen incorporation mechanisms in these nominally anhydrous silicate structures.

    Related items

    Showing items related by title, author, creator and subject.

    • A study of planar inverted-F antennas in a dielectric enclosure
      He, Jianwei (2006)
      Demand for small and low-profile antennas has greatly increased due to the desire for miniaturisation of modern-day mobile radio electronic terminals. Such an antenna is often integrated into the dielectric casing of a ...
    • Proton Mobility in the In-Doped CaZrO3 Perovskite Oxide
      Bilic, Ante; Gale, Julian (2007)
      First-principles calculations, based on density functional theory, are exploited to investigate the mechanisms and energetics of proton mobility in CaZrO3. The computations accurately reproduce the observed orthorhombic ...
    • Acoustics of Partially Saturated Rocks: Theory and Experiments
      Muller, T.; Caspari, E.; Qi, Q.; Rubino, J.; Velis, D.; Lopes, S.; Lebedev, Maxim; Gurevich, Boris (2015)
      The presence of fluids in the pore space of rocks causes wave attenuation and dispersion by the mechanism broadly known as wave-induced fluid flow (WIFF). WIFF occurs as a seismic wave that creates pressure gradients ...
    Advanced search

    Browse

    Communities & CollectionsIssue DateAuthorTitleSubjectDocument TypeThis CollectionIssue DateAuthorTitleSubjectDocument Type

    My Account

    Admin

    Statistics

    Most Popular ItemsStatistics by CountryMost Popular Authors

    Follow Curtin

    • 
    • 
    • 
    • 
    • 

    CRICOS Provider Code: 00301JABN: 99 143 842 569TEQSA: PRV12158

    Copyright | Disclaimer | Privacy statement | Accessibility

    Curtin would like to pay respect to the Aboriginal and Torres Strait Islander members of our community by acknowledging the traditional owners of the land on which the Perth campus is located, the Whadjuk people of the Nyungar Nation; and on our Kalgoorlie campus, the Wongutha people of the North-Eastern Goldfields.