液态硝基甲烷热分解行为及压力效应的第一性原理研究

采用基于密度泛函理论的第一性原理分子动力学方法对液态硝基甲烷的热分解行为进行了模拟，结合各产物布居数随时间的演化，讨论了热分解初期可能发生的3种反应，即分子内/分子间的质子迁移反应和C—N键的断裂.在长时间（30 ps）的模拟过程中，H₂O是主要产物.研究了液态硝基甲烷在不同密度（压力）条件下热分解的动力学行为.发现不同密度（压力）条件下液态硝基甲烷热分解呈现明显不同的变化趋势，并给出了解释. 关键词： 硝基甲烷 分子动力学 热分解 压力效应

First-principles study of thermal decomposition of liquid nitromethane and its compressive effect

Based on the framework of density functional theory，we employed the first-principles molecular dynamics to simulate the thermal decomposition of liquid nitromethane and obtained the time-evolution for the population of decomposition productions. We discussed the three possible reactions at the initial stage of thermal decomposition: intramolecule proton transfer reacton, intermolecule proton transfer reaction, and C—N bond rupture. We also studied the dynamic behavior of thermal decomposition of liquid nitromethane under different density （pressure） conditions. We found that the thermal decomposition of liquid nitromethane sensitively depends on the liquid density of pressure. A possible explanation was given.