So iron in the core is all sewn up Ö.or is it?!!
Many groups favour bcc-Fe as the stable phase - there may be a break in slope of Tm at high P.
It is possible that bcc could be stabilised by T.
Therefore we have performed free energy calculations on bcc-Fe as a f(V,T).
But this is difficult - how do you get harmonic F?
Answer: use TI between mechanically stable reference system and high T system.