The thermal and caloric properties of crystalline argon along the sublimation line are calculated in the present work. For this purpose, a correlation cell-cluster expansion is used. Along the sublimation line, there is a monotonic increase in the molar volume, as well as in the pressure with increasing temperature. At the same time, for temperatures below 60 K, the pressure becomes 100 times lower than the triple point pressure, and then rapidly decreases. As for the molar volume, it remains virtually constant at temperatures below 10 K. The heat capacity at constant pressure for the crystalline phase increases monotonically with increasing temperature. A comparison of the theoretical data with the experimental data is performed, and good agreement is obtained for all considered regions, except in the case of the heat capacity at temperatures below 3 K, where collective interactions must be taken into account.
P. N. Nikolaev (Mon,) studied this question.