High-Energy-Density AsN8 with Topologically Folded N18 Rings

Nitrogen-rich compounds have attracted considerable attention due to their potential applications as high-energy-density materials. The compositional complexity and pressure-dependent behavior of these systems make them a particularly intriguing subject for fundamental and applied research. In this work, we focus on the reactivity among group-V nitrogen analogues and systematically explore the As-N system at a 1:8 stoichiometry using first-principles calculations over a pressure range of 0 to 100 GPa. Our results reveal a sequence of pressure-induced phase transitions culminating in a P3 ̵̅c1 phase, whose structural unit consists of topologically folded N18 rings. This novel configuration exhibits outstanding energy storage properties, with a mass energy density of 6.06 kJ/g, significantly surpassing conventional explosives such as TNT (4.30 kJ/g) and HMX (5.70 kJ/g). Theoretical estimates of detonation performance indicate a detonation velocity of 22.88 km/s and a detonation pressure of 357.60 GPa. These results demonstrate the promise of AsN8 as a next generation high-energy-density material and provide a structural basis for the rational design of novel nitrogen-rich energetic compounds.