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.

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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