High-pressure new phase of AgN₃

The structural evolutionary behaviors of AgN₃ have been studied by using the particle swarm optimization structure search method combined with the density functional theory. One stable high-pressure metal polymeric phase with the [Formula: see text] space group is suggested. The enthalpy difference analysis indicates that the Ibam-AgN₃ phase will transfer to the I4/mcm-AgN₃ phase at 4.7 GPa and then to the [Formula: see text]-AgN₃ phase at 24 GPa. The [Formula: see text]-AgN₃ structure is composed of armchair–antiarmchair N-chain, in which all the N atoms are sp² hybridization. The inherent stability of the armchair–antiarmchair chain and the anion–cation interaction between the N-chain and Ag atom induce a high stability of the [Formula: see text]-AgN₃ phase, which can be captured at ambient conditions and hold its stable structure up to 1400 K. The exhibited high energy density (1.88 KJ/g) and prominent detonation properties ([Formula: see text] Km/s; [Formula: see text] GPa) of the [Formula: see text]-AgN₃ phase make it a potentially high energy density material.