摘要：The polymerization of nitrogen can be used as high energy density materials. The crystal structures of Li2N2 at high pressures are explored by using the first-principles method combined with evolutionary algorithm. The phase transitions Pmmm → Immm → Pnma → Cmcm-1 → I41/acd are predicted in the pressure range of 0–300 GPa. Enthalpy calculations reveal that the tetragonal phase I41/acd containing the spiral nitrogen chains is stable above 242 GPa, indicating that the polymerization of nitrogen is realized in Li2N2 under pressure.
