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Science 14 October 2005:
Vol. 310. no. 5746, pp. 297 - 299
DOI: 10.1126/science.1116952
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Reports

Structure and Freezing of MgSiO3 Liquid in Earth's Lower Mantle

Lars Stixrude1*{dagger} and Bijaya Karki2

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.

1 Department of Earth and Planetary Science, University of California, Berkeley, CA 94720, USA.
2 Department of Computer Science, Louisiana State University, Baton Rouge, LA 70803, USA.

* On leave from Department of Geological Sciences, University of Michigan, Ann Arbor, MI 48109, USA.

{dagger} To whom correspondence should be addressed. E-mail: stixrude{at}umich.edu

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