How are light elements present in Earth’s core? An ab initio systematic exploration.

ORAL

Abstract

The composition of the light-element phase of the Earth's inner core remains controversial. In the present work we perform a systematic ab initio study of the possible forms that this light-element phase can show at the conditions of the inner core, including FenX (n=1...5; X=S,Mg,H,C,O) compounds. We have performed automated crystalline structure searches for FenX compounds using CALYPSO, and relaxed the candidate structures using VASP. We plotted the convex hulls for the compounds of Fe with each light element, and found the thermodynamically stable compounds at the conditions of the inner core. We calculated their thermal properties and density using phonon analysis and a quasi-harmonic approximation. We finally estimated the maximum abundance of the light elements in the core by comparing their compounds' densities with pure bcc-Fe and the actual density of the inner core. The results are consistent with literature findings for the outer core.(1)

1. Badro J, Cote AS, & Brodholt JP (2014) A seismologically consistent compositional model of Earth's core. Proceedings of the National Academy of Sciences of the United States of America 111(21):7542-7545.

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Presenters

  • Jorge Botana

    • Beijing Computational Science Research Centre
    • Beijing Computational Science Research Center

Authors

  • Jorge Botana

    • Beijing Computational Science Research Centre
    • Beijing Computational Science Research Center

  • Zhen Liu

    • Division of Simulation of Physical Systems, Beijing Computational Research Center
    • Beijing Computational Science Research Centre
    • Beijing Computational Science Research Center

  • Frank Spera

    • Department of Earth Science, University of California Santa Barbara
    • Earth Science, University of California Santa Barbara

  • Matthew Jackson

    • Department of Earth Science, University of California Santa Barbara
    • Earth Science, University of California Santa Barbara

  • Hai-Qing Lin

    • Beijing Computational Science Research Center
    • Division of Simulation of Physical Systems, Beijing Computational Research Center
    • Beijing Computational Science Research Centre

  • Maosheng Miao

    • California State University Northridge
    • Department of Chemistry and Biochemistry, California State University, Northridge
    • Department of Chemistry and Biochemistry, California State University Northridge
    • California State University, Northridge
    • Chemistry and Biochemistry, California State University Northridge