No abstract

Polynitrogen compounds have been intensively studied for potential applications as high energy density materials, especially in energy and military fields. Here, using the swarm intelligence algorithm in combination with first-principles calculations, we systematically explored the variable stoichiometries of yttrium–nitrogen compounds on the nitrogen-rich regime at high pressure, where a new stable phase of YN10 adopting I4/m symmetry was discovered at the pressure of 35 GPa and showed metallic character from the analysis of electronic properties. In YN10, all the nitrogen atoms were sp2-hybridized in the form of N5 ring. Furthermore, the gravimetric and volumetric energy densities were estimated to be 3.05 kJ/g and 9.27 kJ/cm-1 respectively. Particularly, the calculated detonation velocity and pressure of YN10 (12.0 km/s, 82.7 GPa) was higher than that of TNT (6.9 km/s, 19.0 GPa) and HMX (9.1 km/s, 39.3 GPa), making it a potential candidate as a high-energy-density material.

No abstract