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 ${\text{P=−301+2.215T−5.231×10}}^{\text{−3}}{T}^2{\text{+4.367×10}}^{\text{−6}}{T}^3$ where P is the freezing pressure in kilobars at T°K. The results agree within experimental error with the Simon equation in the form $${\text{(P−21.54)/5.03=(T/354.8)}}^{\text{5.135}}\text{−1,}$$ but the power series fit is better. The main uncertainty in the results is the actual pressure values at the highest pressures.