Institute for Computation in Molecular and Materials Science, School of Chemical Engineering, Nanjing University of Science and Technology, Nanjing 210094, China.
J Chem Phys. 2012 Jan 28;136(4):044516. doi: 10.1063/1.3679384.
We have performed ab initio molecular dynamics simulations in conjunction with the multiscale shock technique to study the initial chemical processes of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) under shock wave loading. The results show that the initial decomposition of shocked HMX is triggered by the N-O bond breaking and the ring opening. This will initiate many decomposition reactions and lead to the production of many small radicals at a moment. As the shock compression continues, these small radicals recombine to produce many large radicals and further form ring-shaped radicals. Then, these radicals begin to further decompose. It is also found that the system transiently produces a large number of metallic states under the shock compression. Our simulations thus suggest a new mechanism for the initial chemical processes of shocked HMX and provide fundamental insight into the initial mechanism at the atomistic level, which is of important implication for understanding and development of energetic materials.
我们结合多尺度激波技术进行了从头算分子动力学模拟，以研究八氢-1,3,5,7-四硝基-1,3,5,7-四唑（HMX）在冲击波加载下的初始化学过程。结果表明，冲击 HMX 的初始分解是由 N-O 键断裂和环开环引发的。这将引发许多分解反应，并在瞬间产生许多小自由基。随着冲击波的继续压缩，这些小自由基重新组合形成许多大自由基，并进一步形成环状自由基。然后，这些自由基开始进一步分解。还发现，在冲击波压缩下，体系会瞬态产生大量金属态。因此，我们的模拟为冲击 HMX 的初始化学过程提供了一个新的机制，并为原子水平的初始机制提供了基本的认识，这对于理解和开发含能材料具有重要意义。
