Sun Zi-Jian, Li Hui, Zhu Weihua
Institute for Computation in Molecular and Materials Science, School of Chemistry and Chemical Engineering, Nanjing University of Science and Technology, Nanjing, 210094, China.
J Mol Model. 2023 Aug 24;29(9):292. doi: 10.1007/s00894-023-05656-8.
Reactive molecular dynamics simulations were performed to study the decomposition processes of 1,3,5-trinitro-1,3,5-triazine (RDX) crystal under high temperatures (2100, 2400, 2700, and 3000 K) and detonation pressure (34.5 GPa) and 0 GPa. It is found that the initial decomposition paths of RDX under different temperatures coupled with detonation pressure are similar, which is due to the N-NO bond breakage to release NO. The formation rates of N and HO are significantly affected by temperature, while those of CO are less influenced. The C atoms finally formed C clusters. As the temperature rises, the decomposition speeds up, indicating that the high temperature accelerates the decomposition. Applying pressure can reduce the reaction energy barrier and accelerate the decomposition.
The RDX model was constructed using the Materials Studio 7.0 package. All MD simulations were performed based on the ReaxFF force field in the LAMMPS software package, and the crystals were visualized using the OVITO software package. The time step was 0.1 fs, and the total MD simulation time was 200 ps. DFT calculations were carried out at the B3LYP/6-311G(d,p) level using the Gaussian 09 package.
进行了反应分子动力学模拟，以研究1,3,5-三硝基-1,3,5-三嗪（RDX）晶体在高温（2100、2400、2700和3000 K）、爆轰压力（34.5 GPa）和0 GPa条件下的分解过程。研究发现，RDX在不同温度与爆轰压力耦合下的初始分解路径相似，这是由于N-NO键断裂释放出NO。N和HO的生成速率受温度影响显著，而CO的生成速率受影响较小。最终C原子形成了C簇。随着温度升高，分解加速，表明高温促进了分解。施加压力可降低反应能垒并加速分解。
使用Materials Studio 7.0软件包构建RDX模型。所有分子动力学模拟均基于LAMMPS软件包中的ReaxFF力场进行，晶体结构使用OVITO软件包进行可视化。时间步长为0.1 fs，分子动力学模拟总时长为200 ps。使用Gaussian 09软件包在B3LYP/6-311G(d,p)水平上进行密度泛函理论计算。
