Hydrogen-bond-driven trigger bond strengthening in CL-20/N8 cocrystal: precise structural prediction for reduced sensitivity and enhanced energy release

CL-20 is one of the most powerful nitramine-based energetic materials, but its high mechanical sensitivity significantly restricts its practical applications. In this work, the CL-20/N8 (1,1′-azo-1,2,3-triazole) cocrystal system is systematically investigated using first-principles calculations and molecular dynamics simulations to identify the stable supramolecular configuration and optimal cocrystal structure. The results demonstrate that strong and cooperative hydrogen-bond interactions form between CL-20 and N8, which redistribute the local electron density and reinforce the weakest N–NO₂ trigger bond of CL-20. This effect markedly enhances structural stability and effectively reduces sensitivity. Furthermore, the rapid energy-release characteristics of N8 promote a more efficient initiation of CL-20 decomposition, leading to an accelerated and more continuous energy-release process. Compared with simple physical mixtures, the CL-20/N8 cocrystal shows both reduced sensitivity and improved energetic performance, confirming the advantages of hydrogen-bond-regulated cocrystallization. These findings provide molecular-level insight into the stabilization and energy-release mechanisms of the CL-20/N8 system and offer guidance for designing next-generation energetic cocrystals with balanced safety and high performance.