Abstract Isothermal-isobaric molecular dynamics (NPT-MD) simulations and density functional theory (DFT) calculations were performed to explore the cocrystal formation mechanism of energetic materials. Based on the morphologically dominant crystal habits of HMX (octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine) and LLM-105 (2,6-diamino-3,5-dinitropyrazine-l-oxide), six interface structures of HMX with LLM-105 have been established to obtain the interaction energy, radial distribution function (RDF), electrostatic potential and mechanical properties. It revealed that the interaction energies in different models are different, owing to the various molecular orientation and stacking manner of the contacted crystal face of HMX and LLM-105. The (1 1 –1)/(1 1 0) interface is mainly governed by the O···H hydrogen bond and strong van der Waals forces and this model possesses the largest interaction energy. Electrostatic potentials indicate (1 1 –1)/(1 1 0) interface blending the strongest, which reveals that the cocrystal process is strongly relevant to the interface behavior of (1 1 –1)/(1 1 0) among the 6 interfaces. Moreover, the mechanical parameters show that the (1 1 –1)/(1 1 0) interface structure (VI) exhibits excellent ductility and fracture strength. Additionally, this work presents a novel insight, which from the crystal face of HMX and LLM-105 as well as the interaction behavior to research the cocrystal mechanism.

中文翻译：

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HMX和LLM-105的共晶机理理论模拟

摘要 进行了等温-等压分子动力学 (NPT-MD) 模拟和密度泛函理论 (DFT) 计算，以探索含能材料的共晶形成机制。基于 HMX（octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine）和 LLM-105（2,6-diamino-3,5-dinitropyrazine-l -氧化物），已经建立了 HMX 与 LLM-105 的六种界面结构，以获得相互作用能、径向分布函数（RDF）、静电势和机械性能。结果表明，由于HMX和LLM-105接触晶面的分子取向和堆积方式不同，不同模型中的相互作用能不同。(1 1 –1)/(1 1 0)界面主要受O…H氢键和强范德华力支配，该模型具有最大的相互作用能。静电势表明 (1 1 –1)/(1 1 0) 界面混合最强，这表明共晶过程与 6 个界面中的 (1 1 –1)/(1 1 0) 界面行为密切相关. 此外，力学参数表明(1 1 –1)/(1 1 0) 界面结构(VI) 表现出优异的延展性和断裂强度。此外，这项工作提出了一个新的见解，从 HMX 和 LLM-105 的晶面以及相互作用行为来研究共晶机制。这表明共晶过程与 6 个界面中 (1 1 –1)/(1 1 0) 的界面行为密切相关。此外，力学参数表明（1 1 –1）/（1 1 0）界面结构（VI）表现出优异的延展性和断裂强度。此外，这项工作提出了一个新的见解，从 HMX 和 LLM-105 的晶面以及相互作用行为来研究共晶机制。这表明共晶过程与 6 个界面中 (1 1 –1)/(1 1 0) 的界面行为密切相关。此外，力学参数表明（1 1 –1）/（1 1 0）界面结构（VI）表现出优异的延展性和断裂强度。此外，这项工作提出了一个新的见解，从 HMX 和 LLM-105 的晶面以及相互作用行为来研究共晶机制。