Second critical point and low-temperature anomalies in the physical properties of water
Ponyatovskii E. G., Sinand V. V., Pozdnyakova T. A.
A metastable P-T phase diagram is calculated for water on the basis of a two-level model. The line of transitions between low-density amorphous ice and high-density amorphous ice terminates at a critical point with the coordinates Гс = 225 K, Pc = 0.33 kbar. The proximity of this critical point to atmospheric pressure is responsible for the low-temperature anomalous behavior seen in the physical properties of water at standard pressure. The temperature dependence of the specific volume and that of the specific heat calculated in this model agree well with experimental data. © 7994 American Institute of Physics.