Geochemistry: Structure and freezing of MgSiO3 liquid in Earth's lower mantle
First-principles molecular-dynamics simulations show that over the pressure regime of Earth's mantle the mean silicon-oxygen coordination number of magnesium metasilicate liquid changes nearly linearly from 4 to 6. The density contrast between liquid and crystal decreases by a factor of nearly 5 over the mantle pressure regime and is 4% at the core-mantle boundary. The ab initio melting curve, obtained by integration of the Clausius-Clapeyron equation, yields a melting temperature at the core-mantle boundary of 5400 ± 600 kelvins.
Publication Source (Journal or Book title)
Stixrude, L., & Karki, B. (2005). Geochemistry: Structure and freezing of MgSiO3 liquid in Earth's lower mantle. Science, 310 (5746), 297-299. https://doi.org/10.1126/science.1116952