We employed ReaxFF molecular dynamics (MD) to simulate the physicochemical properties of HMX nanoparticle at low temperatures. As the temperature increases, its physical and chemical properties change accompanying some transition, which is not reported by any previous studies. The Poisson Scoring Model was used to count phase transition. It is found that the number of the β- to δ-HMX conformational transition at 458 K is higher than that at other temperatures. The types of decomposition products of the HMX nanoparticle at low temperatures are the same as those by pervious high-temperature experiments and theoretical simulations. The decomposition of the HMX nanoparticle is triggered by the C–H bond dissociation. Its decomposition includes two steps. The one is the decay of the HMX molecules, which is called the direct influence of the solid phase; the other one is the second reaction of small intermediate in less condensed phase. Moreover, the temperature will deeply affect the duration of each stage.

我们采用ReaxFF分子动力学（MD）来模拟HMX纳米粒子在低温下的物理化学性质。随着温度的升高，其物理和化学性质会随着某些转变而发生变化，以前的任何研究均未对此进行报道。泊松评分模型用于计算相变。发现β的个数-在458 K时到δ-HMX的构象转变高于其他温度下的构象转变。HMX纳米颗粒在低温下的分解产物类型与以前的高温实验和理论模拟得到的分解产物类型相同。HMX纳米颗粒的分解是由C–H键解离引发的。其分解包括两个步骤。一个是HMX分子的衰变，这称为固相的直接影响。另一个是小中间体在冷凝少的阶段的第二反应。而且，温度将深刻影响每个阶段的持续时间。