Recently, Dreger et al. experimentally investigated the phase diagram and decomposition of 1,1‐diamino‐2,2‐dinitroethene (FOX‐7) single crystal compressed hydrostatically up to 10 GPa and heated over a range of 293–750 K (J. Phys. Chem. C 2016, 120, 11092–11098). As a continuation, we performed ab initio molecular dynamic simulations to study the initiation mechanisms and subsequent decomposition of FOX‐7 at a temperature of 504 K (initial decomposition temperature) coupled with a pressure of 1–5 GPa, 604 K at 5GPa, and 704 K at 5 GPa. However, our two compressing ways are different: the former is static hydrostatical compression, while our way is dynamic compression. Our results indicate that the initial decomposition mechanism was dependent on the temperature but independent of the pressure. The initial decomposition step is the bimolecular intermolecular hydrogen transfer. The subsequent decomposition of FOX‐7 is sensitive to both the temperature and pressure. At 504 K, the decomposition of FOX‐7 was accelerated from 1 to 2 GPa and from 3 to 5 GPa but decelerated from 2 to 3 GPa. The temperature exhibits a positive effect on the decomposition. Overall, the temperature and pressure have great cooperative effects on the decomposition of FOX‐7. Our study may provide new insight into understanding the initial mechanisms and decomposition reactions of energetic materials at relatively low temperatures coupled with different pressures in atomic detail.

中文翻译：

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高温和高压对1,1-二氨基-2,2-二硝基亚乙基晶体分解机理的影响：从头算分子动力学模拟

最近，Dreger等人。实验研究了1,1-二氨基-2-2,2-二硝基乙烯（FOX-7）单晶的相图和分解，该单晶静水压缩至10 GPa，并在293-750 K的范围内加热（J. Phys。Chem。C 2016年，120，11092–11098）。作为继续，我们进行了从头算分子动力学模拟，研究了在504 K（初始分解温度）和1-5 GPa，5 GPa 604 K的压力下FOX-7的引发机理和随后的分解。在5 GPa下为704K。但是，我们的两种压缩方式是不同的：前者是静态静水压缩，而我们是动态压缩。我们的结果表明，初始分解机理取决于温度，但与压力无关。初始分解步骤是双分子分子间氢转移。FOX-7的后续分解对温度和压力均敏感。在504 K时，FOX-7的分解从1 GPa加速到2 GPa，从3 GPa加速到5 GPa，但是从2 GPa减速到3 GPa。温度对分解显示出积极的影响。总体而言，温度和压力对FOX-7的分解具有很大的协同作用。我们的研究可能会提供新的见解，以了解高能材料在相对较低的温度下结合原子细节上的不同压力的初始机理和分解反应。