Trends of the Macroscopic Behaviors of Energetic Compounds: Insights from First-Principles Calculations
Understanding the structure−property relationships of energetic compounds is challenging. Here, by combining with experimental data, we systematically evaluate the microscopic characteristics of a series of transition metal carbohydrazide perchlorates (TMCP) complexes (MnCP, FeCP, CoCP, NiCP, ZnCP, CdCP) by first-principles calculations. The calculated properties, i.e., lattice enthalpy, bulk modulus and electronic structures, are correlated with their thermal decomposition temperature and impact sensitivity, indicating that the stability and sensitivity of the TMCP complexes are greatly changed through coordination with different metal ions. The trend is that, large lattice enthalpy indicates better thermal stability. Complexes with high impact sensitivity tend to have a smaller bulk modulus and pseudo-gap. The ultra high impact sensistivity of FeCP may relate to the unstable spin state with respect to volume change in lattice. The calculated bond order and bond dissociation energy cannot fully reflect the impact and friction sensitivities in this study, and combination of crystal properties and local bond information may better describe the sensitivity trend of TMCP energetic compounds. Such analysis can be applied to other energetic compounds and may provide clues for synthesis and assessment of novel energetic compounds.