Quantum Monte Carlo Calculation for the Equation of State of MgSiO$_{3}$ perovskite at high pressures

ORAL

Abstract

Magnesium silicate (MgSiO$_{3})$ is among the most abundant minerals in the Earth's mantle. Its phase behavior under high pressure has important implications for the physical properties of deep Earth and the core-mantle boundary. A number of experiments and density functional theory calculations have studied perovskite and its transition to the post-perovskite phase. Here, we present our initial work on the equation of state of perovskite at pressures up to 200 GPa using quantum Monte Carlo (QMC), a benchmark ab initio method. Our QMC calculations optimize electron correlation by using a Slater-Jastrow type wave function~with a single determinant comprised of single-particle orbitals extracted from fully converged DFT calculations.~The equation of state obtained from QMC calculations agrees with experimental data.

*E-mail: rcohen@carnegiescience.edu; This work is supported by NSF

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Authors

  • Yangzheng Lin

    • Geophysical Laboratory, Carnegie Institution of Washington, 5251 Broad Branch Road, NW, Washington DC 20015, USA

  • R.E. Cohen

    • Geophysical Lab, Carnegie Institution and UCL
    • Geophysical Lab, Carnegie Inst of Washington, 5251 Broad Branch Road NW, Washington, USA; Dept of Earth Science, University College London, London, UK

  • Kevin Driver

    • University of California, Berkeley
    • Departments of Earth and Planetary Science and of Astronomy, University of California, Berkeley, CA 94720, USA

  • Burkhard Militzer

    • University of California, Berkeley
    • Departments of Earth and Planetary Science and of Astronomy, University of California, Berkeley, CA 94720, USA

  • Luke Shulenburger

    • Sandia National Laboratories
    • Sandia National Laboratories, MS 1189, P.O. BOX 5800 Albuquerque, NM 87185-1189, USA

  • Jeongnim Kim

    • Materials Theory Group, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory
    • Materials Science and Technology Division, Oak Ridge National Laboratory
    • Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA