Melting Curve of Ice VII to 200 kbar

Abstract

The melting curve of ice VII has been determined to 200 kbar, where ice VII melts at 442°C. The curve can be given as P=−301+2.215T−5.231×10−3T2+4.367×10−6T3 where P is the freezing pressure in kilobars at T°K. The results agree within experimental error with the Simon equation in the form (P−21.54)/5.03=(T/354.8)5.135−1,but the power series fit is better. The main uncertainty in the results is the actual pressure values at the highest pressures.