含能材料的从头算分子动力学模拟

Ab Initio Molecular Dynamics Simulation of Energetic Materials

理解含能材料的物理化学性质、爆轰性能及分解机制,对于含能材料的分子设计、安全性评估及实际应用有着重要的指导意义。第一性原理分子动力学不但可以研究含能材料的物理化学性质,还可以用于研究含能材料的分解反应过程。本文综述了当前第一性原理分子动力学模拟含能材料的理论研究进展。首先讨论了含能材料的晶体结构和基本性质,如热学、力学、电学性质和结构的温度、压力效应。随后讨论了含能材料常压下单分子分解行为,侧重讨论了常压下含能材料的热解产物、热解机制及热解反应的动力学性质,其中含能材料的热解起始反应机制主要包括质子转移、C—N键断裂和N—NO2键断裂3种方式。同时,还对静水压、冲击波等加载条件对含能材料热解反应的影响进行了讨论,尤其是冲击波加载可能带来新的反应机制,如C—H键的断裂。

Understanding the physical and chemical properties,detonation properties and decomposition mechanism is very important for molecular design,safety assessment and practical utilization of energetic materials.Ab initio molecular dynamics can be used to not only study the physical and chemical properties,but also understand the decomposition mechanism of energetic materials.The theoretical studies on energetic materials using ab initio molecular dynamics have been reviewed in this paper.Firstly the current progress on crystal structure and basic properties,such as thermal,mechanical and electronic properties,the effect of pressure and temperature on crystal structure of energetic materials are summarized.Then unimolecular decomposition of energetic materials are discussed,especially the products,mechanism and dynamics properties.The main initial reactions of thermal decomposition include proton transfer,C—N bond fission and N—NO2bond cleavage.The effects of hydrostatic pressure,shock wave and other loading conditions on thermal decomposition are also discussed.In particular,shock wave loading may lead up to new reaction mechanism,for example,C—N bond fission.