The structural and thermodynamic properties of CaLi2 at high pressure

In this work, the structural, mechanical and thermodynamic properties of CaLi2 in the pressure range of 0-72GPa have been studied. It was found that CaLi2 undergoes a phase transition from P63/mmc to C2/c phase at 25.37GPa and from C2/c to P21/c phase at 55.99GPa, which is consistent with previous experimental and partially theoretical results. Besides, at 0GPa, the lowest enthalpy appears in both P63/mmc and Fd-3m structures, showing the coexistence of these two phases. However, P63/mmc phase is not stable when the pressure is larger than 6GPa. Finally, the elastic of CaLi2 at different pressures was investigated using the elastic stability criterion, and the thermodynamic properties under different pressures are investigated in detail.

Automated summary

The structural, mechanical, and thermodynamic properties of CaLi2 in the pressure range of 0-72GPa were investigated. It was observed that CaLi2 undergoes phase transitions from P63/mmc to C2/c at 25.37GPa and from C2/c to P21/c at 55.99GPa, which is consistent with previous experimental and theoretical findings. Additionally, a coexistence of P63/mmc and Fd-3m structures with the lowest enthalpy was observed at 0GPa, but P63/mmc phase becomes unstable at pressures larger than 6GPa. The elastic stability and thermodynamic properties under different pressures were also analyzed.