Ambient-stable polymeric nitrogen achieved through multi-stage computational design

The four-decade quest for synthesizing ambient-stable polymeric nitrogen - a promising high-energy-density material - remains an unsolved challenge in materials science. We develop a multi-stage computational strategy employing DFTB-based rapid screening combined with DFT refinement and global structure searching, effectively bridging computational efficiency with quantum accuracy. This integrated approach identifies four novel polymeric nitrogen phases (Fddd, P3₂21, I-4m2, and P6₅22) thermodynamically stable at ambient pressure. Remarkably, the helical P6₅22 configuration demonstrates exceptional thermal resilience up to 1500 K, representing a predicted polymeric nitrogen structure maintaining stability under both atmospheric pressure and high-temperature extremes. Our methodology establishes a paradigm-shifting framework for accelerated discovery of metastable energetic materials, resolving critical bottlenecks in theoretical predictions while providing experimentally actionable targets for polymeric nitrogen synthesis.