What is the form of H in the Earth's inner core?

ORAL

Abstract

Previous work on the possible presence of H in the Earth's inner corefocuses on FeH as the thermodynamically stable form of Fe-H compounds at the pressures of the Earth's core.1 In the present work we have carried out a systematic structure search of the Fe-H compounds at high pressure using a particle swarm optimization algorithm, as implemented in CALYPSO. Each structure has then been studied through ab initio calculations within the framework of the density functional theory, using VASP, and we have obtained the convex hull of the thermodynamically stable compounds. We have found that the Fe-rich compound Fe5H becomes thermodynamically stable at high pressure. This compound is structurally very different from FeH, but similar to the compounds Fe2-4H: it consists of an hcp-Fe lattice with H atoms arranged regularly in the octahedral interstices.

[1] Bazhanova, Z. G. et al., Physics-Uspekhi, 55, 489 (2012)

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Presenters

  • Jorge Botana

    Beijing Computational Science Research Center, California State University, Northridge, Simulation of Physical Systems Division, Beijing Computational Science Research Center

Authors

  • Jorge Botana

    Beijing Computational Science Research Center, California State University, Northridge, Simulation of Physical Systems Division, Beijing Computational Science Research Center

  • Zhen Liu

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

  • Maosheng Miao

    Chemistry and Biochemistry, California State University Northridge, California State University, Northridge, Cal State Univ - Northridge, Chemistry and Biochemistry, California State University, Northridge, Department of Chemistry and Biochemistry, California State University, Northridge

  • Frank Spera

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

  • Matthew Jackson

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