 
Summary: Iron at Earth's core conditions from first principles calculations
Dario Alf`e
Department of Earth Sciences, and Department of Physics and Astronomy,
and London Centre for Nanotechnology, University College London,
Gower Street, London, WC1E 6BT, U.K
June 4, 2010
Abstract
Ab initio techniques, mainly based on the implementation of quantum mechanics known as density func
tional theory, and more recently quantum Monte Carlo, have now become widely used in the investigation
of the high pressure and temperature properties of materials. These techniques have been proven reliable
and accurate, and as such can be considered in many cases as complementary to experiments. Here I will
describe some applications of abinitio techniques to the properties of iron under Earth's core conditions. In
particular, I will focus on the description of how to obtain high pressure and high temperature properties,
as these are the relevant conditions of interests for the Earth's core. Low temperature properties of solids
have often been studied using the quasiharmonic approximation, which sometimes can retain high accuracy
even at temperatures not too far from the melting temperature. However, for solids at high temperature
and for liquids the quasiharmonic approximation fails, and I will describe how using the molecular dynamics
technique, coupled with abinitio calculations and the thermodynamic integration scheme, it is possible to
compute the high temperature thermodynamic properties of both solids and liquids. Examples of the applica
tion of these techniques will include the calculation of many thermodynamic properties of iron and its melting
