Dielectric constant of water under deep Earth pressures and temperature conditions

ORAL

Abstract

The knowledge of the dielectric constant of water as a function of pressure (P) and temperature (T) plays a critical role in understanding the chemistry of aqueous systems, and in particular of fluids in the Earth mantle, where water is stored in hydrous minerals. By using first-principles molecular dynamics, we have computed the dielectric constant of water at T = 1000 K, between 1 and 10 GPa, under conditions of the Earth upper mantle. We present a detailed comparison of our results with available experimental data and empirical models, and we discuss how the liquid dielectric constant is affected by the changes in the hydrogen-bond network and molecular dipole moment observed upon compression.

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Authors

  • Ding Pan

    Department of Chemistry, University of California, Davis

  • Leonardo Spanu

    Department of Chemistry, University of California, Davis, Chemistry Department University of California Davis

  • Francois Gygi

    Department of Computer Science, University of California Davis, Davis CA 95616, Department of Applied Science and Department of Computer Science, University of California, Davis, Department of Computer Science, University of California, Davis

  • Giulia Galli

    University of California, Davis, Department of Chemistry and Department of Physics, University of California, Davis, Department of Chemistry, University of California, Davis; Department of Physics, University of California, Davis, Dep. of Chemistry, UC Davis, Department of Chemistry, University of California, Davis and Department of Physics, University of California, Davis, UC Davis, Department Of Chemistry, Department Of Physics, University of California, Davis, Department of Chemistry, University of California, Davis 95616