Simulation of the Behavior of Calcite under High-Energy Impact Taking into Account Phase Transition

The behavior of calcite at pressures up to 1000 GPa is simulated taking into account the high-pressure phase transition. The shock loading of calcite was calculated using a thermodynamically equilibrium model. A few-parameter Mie–Grüneisen type equation of state is used to describe the behavior of condensed phases. In the phase-transition region, the components of the sample under study are considered as a mixture of low- and high-pressure phases. The single and double shock Hugoniots are constructed in the pressure range from 1 to 1000 GPa, and calculations were made to determined the heat capacity along the normal isobar, entropy as a function of temperature, and the thermodynamic potential along the shock Hugoniot. The simulation results were verified against experimental data and available calculation results.