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Title: Liquid-Vapor Coexistence and Critical Point of Mg2SiO4 From Ab Initio Simulations

Abstract

Hypervelocity impact-driven vaporization is characteristic of late-stage planet formation. Yet the behavior and properties of liquid-vapor mixtures of planetary materials of interest are typically unknown. Multiphase equations of state used in hydrodynamic simulations of planet impacts therefore lack reliable data for this important phenomenon. Here, we present the first constraints on the liquid-vapor critical point and coexistence phase boundary of Mg2SiO4 computed from ab initio molecular dynamics simulations. We found that the vapor is depleted in magnesium and enriched in silica and oxygen, while the coexisting liquid is enriched in magnesium and depleted in oxygen, from which we infer vaporization is incongruent. The critical point was estimated from an equation of state fit to the data. The results are in line with recent calculations of MgSiO3 and together confirm that extant multiphase equation of state (EOS) models used in planetary accretion modeling significantly underestimate the amount of supercritical material postimpact.

Authors:
ORCiD logo [1];  [2];  [1]
  1. Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
  2. Stanford Univ., CA (United States)
Publication Date:
Research Org.:
Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
Sponsoring Org.:
USDOE National Nuclear Security Administration (NNSA)
OSTI Identifier:
1670755
Alternate Identifier(s):
OSTI ID: 1664609
Report Number(s):
SAND2020-8249J
Journal ID: ISSN 0094-8276; 689845
Grant/Contract Number:  
AC04-94AL85000; NA0003864
Resource Type:
Accepted Manuscript
Journal Name:
Geophysical Research Letters
Additional Journal Information:
Journal Volume: 47; Journal Issue: 17; Journal ID: ISSN 0094-8276
Publisher:
American Geophysical Union
Country of Publication:
United States
Language:
English
Subject:
58 GEOSCIENCES

Citation Formats

Townsend, Joshua P., Shohet, Gil, and Cochrane, Kyle R.. Liquid-Vapor Coexistence and Critical Point of Mg2SiO4 From Ab Initio Simulations. United States: N. p., 2020. Web. https://doi.org/10.1029/2020gl089599.
Townsend, Joshua P., Shohet, Gil, & Cochrane, Kyle R.. Liquid-Vapor Coexistence and Critical Point of Mg2SiO4 From Ab Initio Simulations. United States. https://doi.org/10.1029/2020gl089599
Townsend, Joshua P., Shohet, Gil, and Cochrane, Kyle R.. Wed . "Liquid-Vapor Coexistence and Critical Point of Mg2SiO4 From Ab Initio Simulations". United States. https://doi.org/10.1029/2020gl089599. https://www.osti.gov/servlets/purl/1670755.
@article{osti_1670755,
title = {Liquid-Vapor Coexistence and Critical Point of Mg2SiO4 From Ab Initio Simulations},
author = {Townsend, Joshua P. and Shohet, Gil and Cochrane, Kyle R.},
abstractNote = {Hypervelocity impact-driven vaporization is characteristic of late-stage planet formation. Yet the behavior and properties of liquid-vapor mixtures of planetary materials of interest are typically unknown. Multiphase equations of state used in hydrodynamic simulations of planet impacts therefore lack reliable data for this important phenomenon. Here, we present the first constraints on the liquid-vapor critical point and coexistence phase boundary of Mg2SiO4 computed from ab initio molecular dynamics simulations. We found that the vapor is depleted in magnesium and enriched in silica and oxygen, while the coexisting liquid is enriched in magnesium and depleted in oxygen, from which we infer vaporization is incongruent. The critical point was estimated from an equation of state fit to the data. The results are in line with recent calculations of MgSiO3 and together confirm that extant multiphase equation of state (EOS) models used in planetary accretion modeling significantly underestimate the amount of supercritical material postimpact.},
doi = {10.1029/2020gl089599},
journal = {Geophysical Research Letters},
number = 17,
volume = 47,
place = {United States},
year = {2020},
month = {8}
}

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Works referenced in this record:

The nature of dust around the post-asymptotic giant branch objects HD 161796 and HD 179821
journal, June 1992

  • Justtanont, K.; Barlow, M. J.; Skinner, C. J.
  • The Astrophysical Journal, Vol. 392
  • DOI: 10.1086/186429

Generalized Gradient Approximation Made Simple
journal, October 1996

  • Perdew, John P.; Burke, Kieron; Ernzerhof, Matthias
  • Physical Review Letters, Vol. 77, Issue 18, p. 3865-3868
  • DOI: 10.1103/PhysRevLett.77.3865

Vaporization and thermodynamics of forsterite-rich olivine and some implications for silicate atmospheres of hot rocky exoplanets
journal, June 2017


Beyond the Van Der Waals loop: What can be learned from simulating Lennard-Jones fluids inside the region of phase coexistence
journal, December 2012

  • Binder, Kurt; Block, Benjamin J.; Virnau, Peter
  • American Journal of Physics, Vol. 80, Issue 12
  • DOI: 10.1119/1.4754020

Planetesimals to planets: Numerical simulation of collisional evolution
journal, July 1978


Ab initio simulation of the metal/nonmetal transition in expanded fluid mercury
journal, March 1997


Quantum Molecular Dynamics Simulations for Generating Equation of State Data
conference, January 2009

  • Desjarlais, Michael P.; Fournier, Kevin B.
  • ATOMIC PROCESSES IN PLASMAS: Proceedings of the 16th International Conference on Atomic Processes in Plasmas, AIP Conference Proceedings
  • DOI: 10.1063/1.3241205

Efficient iterative schemes for ab initio total-energy calculations using a plane-wave basis set
journal, October 1996


Ab initio molecular-dynamics simulation of the liquid-metal–amorphous-semiconductor transition in germanium
journal, May 1994


Direct determination of phase coexistence properties of fluids by Monte Carlo simulation in a new ensemble
journal, July 1987


Diffusion and viscosity of Mg2SiO4 liquid at high pressure from first-principles simulations
journal, August 2011


A computer simulation study of the liquid–vapor coexistence curve of water
journal, May 1993

  • Guissani, Yves; Guillot, Bertrand
  • The Journal of Chemical Physics, Vol. 98, Issue 10
  • DOI: 10.1063/1.464527

The Principal Hugoniot of Forsterite to 950 GPa
journal, May 2018

  • Root, Seth; Townsend, Joshua P.; Davies, Erik
  • Geophysical Research Letters, Vol. 45, Issue 9
  • DOI: 10.1029/2017GL076931

Lunar-forming impacts: High-resolution SPH and AMR-CTH simulations
journal, January 2013


Ab initiomolecular dynamics for liquid metals
journal, January 1993


The State of the Cubic Equations of State
journal, April 2003

  • Valderrama, José O.
  • Industrial & Engineering Chemistry Research, Vol. 42, Issue 8
  • DOI: 10.1021/ie020447b

Shock vaporization of silica and the thermodynamics of planetary impact events: SHOCK VAPORIZATION OF SILICA
journal, September 2012

  • Kraus, R. G.; Stewart, S. T.; Swift, D. C.
  • Journal of Geophysical Research: Planets, Vol. 117, Issue E9
  • DOI: 10.1029/2012JE004082

The structure of terrestrial bodies: Impact heating, corotation limits, and synestias: THE STRUCTURE OF TERRESTRIAL BODIES
journal, May 2017

  • Lock, Simon J.; Stewart, Sarah T.
  • Journal of Geophysical Research: Planets, Vol. 122, Issue 5
  • DOI: 10.1002/2016JE005239

Thermal Properties of the Inhomogeneous Electron Gas
journal, March 1965


Forming a Moon with an Earth-like Composition via a Giant Impact
journal, October 2012


Liquid-vapor phase relations in the Si-O system: A calorically constrained van der Waals-type model: Liquid-Vapor Phase Relations in the Si-O System
journal, September 2016

  • Connolly, James A. D.
  • Journal of Geophysical Research: Planets, Vol. 121, Issue 9
  • DOI: 10.1002/2016JE005059

Thermodynamics, structure, dynamics, and freezing of Mg2SiO4 liquid at high pressure
journal, March 2008

  • de Koker, Nico P.; Stixrude, Lars; Karki, Bijaya B.
  • Geochimica et Cosmochimica Acta, Vol. 72, Issue 5
  • DOI: 10.1016/j.gca.2007.12.019

Evaluation of aluminum critical point using an ab initio variational approach
journal, April 2009

  • Faussurier, Gérald; Blancard, Christophe; Silvestrelli, Pier Luigi
  • Physical Review B, Vol. 79, Issue 13
  • DOI: 10.1103/PhysRevB.79.134202

Large impacts around a solar-analog star in the era of terrestrial planet formation
journal, August 2014


Making the Moon from a Fast-Spinning Earth: A Giant Impact Followed by Resonant Despinning
journal, October 2012


Critical vaporization of MgSiO 3
journal, May 2018

  • Xiao, Bing; Stixrude, Lars
  • Proceedings of the National Academy of Sciences, Vol. 115, Issue 21
  • DOI: 10.1073/pnas.1719134115

Extending the accuracy of the SNAP interatomic potential form
journal, June 2018

  • Wood, Mitchell A.; Thompson, Aidan P.
  • The Journal of Chemical Physics, Vol. 148, Issue 24
  • DOI: 10.1063/1.5017641

Silicate Melting and Vaporization During Rocky Planet Formation
journal, February 2020

  • Davies, E. J.; Carter, P. J.; Root, S.
  • Journal of Geophysical Research: Planets, Vol. 125, Issue 2
  • DOI: 10.1029/2019JE006227

Evaporation of olivine: Low pressure phase relations of the olivine system and its implication for the origin of chondritic components in the solar nebula
journal, April 1994


A theoretically correct mixing rule for cubic equations of state
journal, May 1992


The shock physics of giant impacts: Key requirements for the equations of state
conference, January 2020

  • Stewart, Sarah; Davies, Erik; Duncan, Megan
  • SHOCK COMPRESSION OF CONDENSED MATTER - 2019: Proceedings of the Conference of the American Physical Society Topical Group on Shock Compression of Condensed Matter, AIP Conference Proceedings
  • DOI: 10.1063/12.0000946