Berlin 2015 – wissenschaftliches Programm
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DY: Fachverband Dynamik und Statistische Physik
DY 17: Modeling and Data Analysis
DY 17.1: Vortrag
Dienstag, 17. März 2015, 09:30–09:45, BH-N 333
Structure, equation of state and transport properties of molten calcium carbonate (CaCO_3) from atomistic simulations — Rodolphe Vuilleumier1, •Ari Paavo Seitsonen1,2, Nicolas Sator3, and Bertrand Guillot3 — 1Département de Chimie, École Normale Supérieure Paris, France — 2Institut für Chemie, Universität Zürich, Switzerland — 3Sorbonne Universités, Université Paris 6 et CNRS, UMR 7600, LPTMC, Paris, France
We have performed first-principle molecular dynamics (FPMD) simulations to evaluate the physical properties (liquid structure, density, atomic vibrational motion, diffusion coefficients and electrical conductivity) of liquid calcium carbonate (CaCO_3), which are up to now poorly known. As compared with silicate melts, molten CaCO_3 is characterized by a low density, a viscosity almost as low as that of water and a high conductivity. An empirical force field has been developed for predicting the properties of molten CaCO_3 at any state point in the liquid stability field and used in classical MD simulations, from which the equation of state and the phase diagram of the liquid phase have been obtained. The self diffusion coefficients, viscosity, and the electrical conductivity with pressure and temperature have been investigated and the results fitted to analytical forms. It is shown that the Stokes-Einstein equation, expressing the viscosity as a function of diffusion motion, is followed and that the Nernst-Einstein equation relating the electrical conductivity to the diffusion coefficients of charge carriers leads to an accurate prediction of the conductivity when a constant correcting factor is applied.