Decoding thermal effects on impact sensitivity of energetic materials: Distribution models, response mechanisms, and covalent-noncovalent interaction synergy

Evaluating mechanical sensitivity under thermo-mechanical coupling is essential for defining safety margins of energetic materials in extreme thermal environments. Current deterministic frameworks fail to capture response-probability distributions and overlook underlying temperature-dependent mechanisms. Here, utilizing the complete run-down method, we characterized the relationship between varying impact excitation energies ( x i ) and their corresponding response probabilities ( P ( x i )) to establish probabilistic models for seven energetic materials across 0-100 °C. Integrating quantum-chemical topology and energy-decomposition analyses, we quantified the synergistic roles of covalent and non-covalent interactions. Results show P ( x i ) follows a normal distribution for all materials. Elevated temperature consistently reduces the mean value μ , whereas relative standard deviation (RSD) is material-dependent. Polynitrogen materials show greater sensitivity variation (Δ μ : 2.9-6.6 J; RSD: 14.8-25.3%) and broader transition zones than nitro-compounds (Δ μ : 0.76-2.23 J; RSD: 7.5-14.3%). Theory reveals sensitivity is governed by covalent strength at high temperatures, but modulated by non-covalent forces at lower temperatures. Crucially, the electrostatic-to-dispersion energy ratio (Δ E ele /Δ E disp ) correlates with macroscopic RSD. Electrostatic-dominant polynitrogen crystals experience localized thermally induced collapse, leading to significant sensitivity dispersion, whereas dispersion-dominated nitro-systems maintain uniform responses. This work delivers probabilistic models linking electron-density topology to macroscopic stochastic behavior, establishing dynamic-threshold criteria to guide intrinsic-safety design of next-generation energetic materials. 1 Temperature-dependent probability models replace single-value metrics to map energetic material sensitivity. 2. Room-temperature tests misjudge polynitrogen safety, as thermal effects severely weaken non-covalent buffering. 3. Covalent and non-covalent synergy quantitatively links macroscopic sensitivity distributions to micro-mechanisms.