Comparative study on high-pressure physical properties of monoclinic MgCO and MgCO.

The physical properties of Mg-carbonate at high temperature and pressure are crucial for understanding the deep carbon cycle. Here, we use first-principles calculations to study the physical properties of MgCO-C2/m and MgCO-P2/c under high pressure. The research shows that the structure and equation of state of MgCO-C2/m are in good agreement with the experimental results, and the phase transition pressure of MgCO from pnma to P2/c structure is 44.