Speaker
Martin French
Description
See the full Abstract at http://ocs.ciemat.es/EPS2018ABS/pdf/I2.J202.pdf
Equation of state and transport properties of water plasmas from ab initio
simulations
M. French1 , R. Redmer1
1 Universität Rostock, Rostock, Germany
The equation of state (EOS) and transport properties of dense water plasmas are of fun-
damental importance for understanding the interior structure and magnetic-field generation in
water-rich giant planets like Uranus and Neptune. Ab initio molecular dynamics simulations
based on density functional theory (DFT-MD simulations) have proven to be an efficient and
accurate method to calculate such thermodynamic and transport properties of water plasmas.
This method also allows for a consistent description of transformations from the plasma state to
dissociated or molecular fluid states as well as to a superionic solid at high density [1].
This talk will give an overview about the phase diagram, the EOS and the electrical conduc-
tivity of warm dense water as derived from DFT-MD simulations. It is shown that the results
for the EOS and optical conductivity are in good agreement with shock-wave compression ex-
periments [2].
The description of low-density states ≤ 0.1 g/cm3 is still hardly feasable with DFT-MD due
to computational limitations. Therefore, we also report on investigations on finding a possible
region of overlap between DFT-MD data and results from a partially ionized plasma model for
low densities [3, 4]. It will be shown that both approaches share a region of reasonable, albeit
not perfect overlap, so that the construction of wide-range models for the EOS and conductivity
remains yet a challenge.
This work is supported by the DFG within the FOR 2440 "Matter under Planetary Interior
Conditions - High Pressure, Planetary, and Plasma Physics."
References
[1] R. Redmer, T.R. Mattsson, N. Nettelmann, M. French, Icarus 211, 798 (2011)
[2] M.D. Knudson, M.P. Desjarlais, R.W. Lemke, T.R. Mattsson, M. French, N. Nettelmann, R. Redmer, Phys.
Rev. Lett. 108, 091102 (2012)
[3] M. Schöttler, R. Redmer, M. French, Contrib. Plasma Phys. 53, 336 (2013)
[4] M. French, R. Redmer, Phys. Plasmas 24, 092306 (2017)
