CALTECH ASCI TECHNICAL REPORT 116 cit-asci-tr116 Reply to "Comment on 'The Phase Diagram of MgO from Density Functional Theory and Molecular Dynamics Simulations' "

In answer to a Comment by Belonoshko [Phys. Rev. B (to be published)], we show that the B1-liquid melting curve of MgO obtained using two-phase simulations is in good agreement with the published one obtained using the Clausius-Clapeyron equation in conjunction with separate single phase calculations of liquid and solid. The main point of the Comment by Belonoshko [1] regards the calculation of melting curves from Molecular Dynamics (MD) simulations. In our paper [2] we calculated the melting curve Tm(P ) by integrating the Clausius-Clapeyron (CC) equation (dP=dT = 1=T H= V ), which relates the slope of the melting curve to the change in enthalpy and volume between the liquid and solid phases. The quantities H and V were calculated via MD simulations using the qMS-Q Force Field derived from quantum mechanical calculations. The H and V data was obtained by heating the solid well into the liquid region and then cooling the liquid well into the solid region, leading to a range of temperatures where both liquid and solid properties can be calculated. This integration method Author to whom correspondence should be addressed