High-pressure new phase of AgN₃

Abstract

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.

The New High-Pressure Phases of Nitrogen-Rich Ag–N Compounds

“…At 50 and 100 GPa, the reported P-1-AgN 3 in Ref. [ 65 ] is also found in this work. For the AgN 7 stoichiometry, the thermodynamically stable P1 and P-1 phases are found at 50 GPa and 100/150 GPa, respectively.…”

“…[ 62 , 63 , 64 ]. Recently, the armchair–antiarmchair N-chain and N 5 ring structures are severally reported for AgN 3 and AgN 5 /AgN 6 compounds [ 65 , 66 ]. Beyond that, no other new silver nitrides with the high-pressure polymeric structures have been reported.…”

Prediction of metastable phase of the Sc–N system in the N-rich region under high pressure

“…The calculation of phonon frequency is carried out by using the finite displacement approach through the PHONOPY code to determine the dynamic stability of the studied structures. 30,31 First principles molecular dynamics (FPMD) to examine the thermal stability of structures is performed at constant number of molecules N (2 Â 2 Â 2 supercell, 96 atoms), constant volume V and constant temperature T (NVT-ensemble). 30 The integrator is the Verlet method in FPMD by using the VASP code.…”

New Transformation Pathway of cg-N from HeN4 under Moderate Pressure

“…The plane-wave cutoff energy and Monkhorst–Pack K-meshes are 520 eV and 2π × 0.03 Å –1 , respectively. , The calculation of the phonon frequency is carried out using the CASTEP module implemented in the Material Studio software package . Ab initio molecular dynamics (AIMD) simulation is performed in the NPT ensemble . The Nose–Hoover thermostat is adopted to control and adjust the temperature of the simulated system.…”

“…39 Ab initio molecular dynamics (AIMD) simulation is performed in the NPT ensemble. 40 The Nose− Hoover thermostat is adopted to control and adjust the temperature of the simulated system. The simulated time of one period is 10 ps with a time step of 1 fs.…”