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.
Stixrude
Lars
L
Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA. stixrude@umich.edu
Karki
Bijaya
B