Thermal conductivity of MgO at lower mantle conditions from ab initio calculations.

Geodynamical models indicate that thermal conductivity plays a significant role in determining the structure and dynamics of the Earth's mantle. In addition, because the thermal conductivity of the mantle regulates the heat flux from the core, it also effects magnetic field generation. In spite of this, the thermal conductivity of mantle minerals at the relevant pressures is unknown, due to difficulties in making measurements at such extreme conditions. In view of this, we have calculated the lattice thermal conductivity of MgO using a reverse perturbation steady-state non-equilibrium molecular dynamics method, with the forces driving the dynamics being computed within density functional theory. In the first case, calculations were carried out at temperatures of 1000 K and 2000 K at ambient pressures, in order to allow compare with experimental results. Following this values were calculated at 2000 K and 4000 K at 136 GPa. Calculations for MgSiO3 perovskite are ongoing. The method will be discussed and results presented.