Melting slope of MgO from molecular dynamics and density functional theory

摘要

We combine density functional theory (DFT) with molecular dynamicssimulations based on an accurate atomistic force field to calculate thepressure derivative of the melting temperature of magnesium oxide at ambientpressure - a quantity for which a serious disagreement between theory andexperiment has existed for almost 15 years. We find reasonable agreement withprevious DFT results and with a very recent experimental determination of theslope. We pay particular attention to areas of possible weakness in theoreticalcalculations and conclude that the long-standing discrepancy with experimentcould only be explained by a dramatic failure of existing density functionalsor by flaws in the original experiment.