Ion Solvation at Thermodynamic Extremes from First Principles

ORAL

Abstract

The properties of aqueous salt solutions at high pressure and temperature are crucial to understanding geochemically relevant fluids. We report on the properties of aqueous monovalent ions at high pressure and temperature (1 GPa/1000 K, 11 GPa/1000 K), as obtained from first-principles molecular dynamics simulations [1]. In particular, we discuss the effect of ions on the structure and diffusion of water and the effect of water dissociation occurring under pressure, on ion solvation. We further analyze vibrational signatures of solvated ions, by comparing computed infrared and Raman spectra of salty and pure water [2] at the same conditions. Finally we present results for ionic conductivity and dielectric constants.

[1] http://qboxcode.org
[2] V. Rozsa, D. Pan, F. Giberti, and G. Galli, Proc. Natl. Acad. Sci. USA, 201800123, (2018).

*We acknowledge support from the DOE NNSA Stewardship Science Graduate Fellowship under grant number DE-NA0003864 and MICCoM as part of the Computational Materials Sciences Program funded by the US Department of Energy, Office of Science, Basic Energy Sciences, Materials Sciences and Engineering Division.

–

Presenters

  • Viktor Rozsa

    • Institute for Molecular Engineering, Univ. of Chicago

Authors

  • Viktor Rozsa

    • Institute for Molecular Engineering, Univ. of Chicago

  • Giulia Galli

    • Institute for Molecular Engineering, University of Chicago
    • Institute for Molecular Engineering and Materials Science Division, University of Chicago and Argonne National Laboratory
    • University of Chicago, Argonne National Lab
    • Institute for Molecular Engineering and Department of Chemistry, University of Chicago
    • University of Chicago and Argonne National Laboratory
    • The Institute for Molecular Engineering, University of Chicago
    • University of Chicago
    • Institute for Molecular Engineering, Univ. of Chicago; Department of Chemistry, Univ. of Chicago; Materials Science Division, Argonne National Laboratory