Wang Jianhua, Wang Shuya, Zhou Jiaxuan, Li Hang, Yu Yanwu
College of Environment and Safety Engineering, North University of China, Taiyuan, 030051, China.
Chuannan Energy Technology Co., Ltd., Luzhou, 646604, China.
J Mol Model. 2025 Aug 25;31(9):254. doi: 10.1007/s00894-025-06476-8.
CL-20 (especially the ε-crystal form) is a high-energy density explosive, but the preparation of centimeter-sized ε-CL-20 crystals is complex, which limits the study of its properties and mechanisms. Since crystal morphology can significantly affect the performance and sensitivity of energetic materials, this study combines MD simulation and experimental techniques to study and examine the differences in ε-CL-20 crystal habit as well as the interplay between the principal growing crystal planes of ε-CL-20 and the mixed solvent molecules. The findings reveal that according to the AE model, ε-CL-20 consists of (0 1 1), (1 1 0), (1 0 -1), (1 1 -1), (0 0 2), (0 2 1), and (1 0 1) seven independent surfaces under vacuum, and the (0 1 1) surface is the most important growth surface. During the crystallization process of ε-CL-20 in three mixed solvents, the (0 1 1) surface remains an important crystal surface due to its low modified attachment energy. Also, the impact of the solvent component on the morphology of the crystal is more significant compared to that of the non-solvent component. The size of the crystal cultured in the experiment can reach centimeter level and is consistent with the simulated morphology. The X-ray diffraction patterns show that the synthesized crystals were in the ε form, and the sections are (0 1 1) surface. This study provides a novel approach for cultivating large ε-CL-20 crystals, paving the way for further studies on its performance and mechanism.
The ε-CL-20 crystal morphologies were obtained within a vacuum and different binary mixed solvent environments under COMPASS force field utilizing the AE model via the MD method on the Materials Studio 2019 platform. The complete simulation was generated using the NTV system. The temperature control method was chosen as Anderson, whereas the temperature of the system was set as 298 K. The data were acquired after every 5000 steps and the step size was 1 fs, while the total time of the simulation was equal to 100 ps.
六硝基六氮杂异伍兹烷（CL-20，尤其是ε晶型）是一种高能量密度炸药，但制备厘米尺寸的ε-CL-20晶体很复杂，这限制了对其性能和机理的研究。由于晶体形态会显著影响含能材料的性能和敏感度，本研究结合分子动力学（MD）模拟和实验技术，研究并考察ε-CL-20晶体习性的差异，以及ε-CL-20主要生长晶面与混合溶剂分子之间的相互作用。研究结果表明，根据AE模型，ε-CL-20在真空中由（0 1 1）、（1 1 0）、（1 0 -1）、（1 1 -1）、（0 0 2）、（0 2 1）和（1 0 1）七个独立表面组成，且（0 1 1）表面是最重要的生长表面。在ε-CL-20于三种混合溶剂中的结晶过程中，（0 1 1）表面因其较低的修正附着能而仍然是重要的晶体表面。此外，与非溶剂成分相比，溶剂成分对晶体形态的影响更为显著。实验培养的晶体尺寸可达厘米级别，且与模拟形态一致。X射线衍射图谱表明合成的晶体为ε晶型，且截面为（0 1 1）表面。本研究为培养大尺寸ε-CL-20晶体提供了一种新方法，为进一步研究其性能和机理铺平了道路。
在Materials Studio 2019平台上，利用AE模型通过MD方法在COMPASS力场下，在真空和不同二元混合溶剂环境中获得ε-CL-20晶体形态。使用NTV系统进行完整模拟。温度控制方法选择安德森方法，系统温度设定为298 K。每5000步采集一次数据，步长为1 fs，模拟总时间为100 ps。
