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.

*DOE/SciDAC-e: DE-FC02-06ER25777

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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