Interception of chain shape Ce nitrides at ambient conditions

A high-pressure study of the CeN5 compounds is performed by the crystal structure search method in combination with the first principle calculations. Four new phases C2-CeN5, P-1-CeN5, P2/c- CeN5, and P21/m-CeN5 were predicted at 0, 20, 50, and 100 GPa, respectively. The analysis of stability shows that C2-CeN5, P-1-CeN5, and P21/m-CeN5 can be quenched to ambient conditions. The stabilization mechanism of Ce nitrides is clarified by the analysis of electronic structures. The phase transformation of CeN5 with the pressure is revealed by the enthalpy difference analysis. P2/c-CeN5 and P21/m-CeN5 with polymeric N-chains not only exhibit high energy densities (8.67 and 9.37 kJ/cm3), but also outstanding detonation velocities (11.43 and 12.10 km/s) and deto-nation pressures (90.39 and 102.82 GPa).