Sun Kang-Bo, Zhang Shu-Hai, Ren Fu-de, Hao Yong-Ping, Ba Shu-Hong
School of Environment and Safety Engineering, North University of China, Taiyuan, 030051, China.
School of Equipment Engineering, Shenyang Ligong University, Shenyang, 110159, China.
J Mol Model. 2021 Feb 17;27(3):85. doi: 10.1007/s00894-020-04634-8.
In order to add safely external electric fields into the systems of the explosives with strong cage strain, the effects of the external electric fields on the strengths of trigger linkages, cage strain energies (CSEs), surface electrostatic potentials (ESPs), as well as impact and shock initiation sensitivities of CL-20 were investigated using the B3LYP and M06-2X methods with 6-311++G(2d,p) basis set. The results show that the changes of the strengths of the N-NO bonds are more notable than those of the bonds forming cage, and the changes involving the N-NO bonds attached to the five-membered ring are more significant than those attached to the six-membered ring. In most cases, the CSEs in the electric fields are stronger than those in no field. From the BDEs, the N-NO cleavage is the decomposition reaction pathway in detonation initiation. However, from the surface ESPs, the N-NO cleavage, C-N and C-C bond breaking may initiate the reactions. The global ESPs are more reasonable and reliable to estimate the impact sensitivities of the cage-shaped explosives. The changes of the bond lengths, Mulliken bond orders, nitro group charges and BDEs correlate well with the external electric field strengths. Interestingly, an abnormal result is found that the h values in the electric fields are larger than those in no field.
为了安全地将外部电场引入具有强笼状应变的炸药体系中，采用B3LYP和M06 - 2X方法以及6 - 311++G(2d,p)基组，研究了外部电场对CL - 20的触发键强度、笼状应变能（CSEs）、表面静电势（ESPs）以及冲击和爆轰起爆敏感性的影响。结果表明，N - NO键强度的变化比形成笼状结构的键的变化更显著，且与五元环相连的N - NO键的变化比与六元环相连的更显著。在大多数情况下，电场中的CSEs比无电场时更强。从键解离能来看，N - NO键的断裂是爆轰起爆中的分解反应途径。然而，从表面ESPs来看，N - NO键的断裂、C - N键和C - C键的断裂都可能引发反应。整体ESPs对于估算笼状炸药的冲击敏感性更为合理和可靠。键长、Mulliken键级、硝基电荷和键解离能的变化与外部电场强度具有良好的相关性。有趣的是，发现了一个异常结果，即电场中的h值比无电场时更大。
