First-Principles Molecular Dynamics Simulations ofSilicate Melts: Structural and Dynamical Properties

摘要

The study of silicate melts from first principles is computationally intensive due to theneed of relatively large atomic systems and long simulation runs. Recent advances in hardwareand software have made it possible to accurately simulate the liquid phase at pressures andtemperatures that are geophysically relevant. This paper reports the details of the methodologyused in the context of simulations and subsequent analysis of the output data. The simulationsare performed using the parallel first-principles molecular dynamics (FPMD) technique withinthe framework of density functional theory. Various physical properties including the equationof state, thermodynamics, atomic and electronic structures, self-diffusion and viscosityare obtained from simulations. The position time series are visualized to gain insight intounderlying physical mechanisms. We review the recent first-principles studies of three liquidsalong the MgO-SiO_2 join including MgSiO_3 melt to show that the structural and dynamicalproperties of these liquids are highly sensitive to pressure and temperature.