中性硝基分子几何形状与晶体特性的关联性  

The Correlation Between the Geometric Shape of Neutral Nitro Molecules and their Crystal Properties:a Statistical Study

作　　者：何旭东 张增明[1] 张朝阳[2] 薛向贵 HE Xu-dong;ZHANG Zeng-ming;ZHANG Chao-yang;XUE Xiang-gui(Department of Physics,University of Science and Technology of China,Hefei 230026,China;Institute of Chemical Materials,CAEP,Mianyang621999,China)

机构地区：[1]中国科学技术大学物理系,安徽合肥230026 [2]中国工程物理研究院化工材料研究所,四川绵阳621999

出　　处：《含能材料》2024年第5期501-509,共9页Chinese Journal of Energetic Materials

基　　金：国家自然科学基金资助(22275174,21975236)。

摘　　要：含能晶体堆积结构是影响其感度的重要因素之一,通过晶体中分子层间滑移来缓冲外界刺激是降低含能材料感度的重要机制。为了更好地设计低感高能分子,理解分子的几何形状与其晶体特性的内在关系十分重要。研究以剑桥晶体数据库中的CHNO类中性硝基分子为样本,采用假设检验方法(包括Z检验、t检验和χ2检验)研究了分子的几何形状与其晶体密度、堆积系数及可滑移性之间的关联性。结果表明,在球形、平面和线形分子中,球形分子有最高的晶体密度和堆积系数,但晶体可滑移性较弱;平面度高的平面形分子通过高堆积系数可获得与球形分子相当的晶体密度,同时平面形分子的晶体可滑移性较强,其χ2检验的置信度接近1;线形分子则不如前两者。虽然存在某些高晶体密度和堆积系数的含能晶体不具有可滑移的层状堆积结构,但整体而言,可滑移晶体的晶体密度和堆积系数均比不可滑移晶体大,其Z检验与t检验的置信度均大于0.95,表明通过设计易于发生分子层间滑移的晶体结构来降低其感度与提升晶体密度并不矛盾。平面形分子晶体密度一般较高,与晶体可滑移性强相关,是设计低感高能分子的首选。The packing structure of energetic crystals is one of the important factors affecting their sensitivity.A crucial mecha-nism for reducing the sensitivity of energetic materials is buffering external stimuli through the slipping between molecular layers within the crystal.It is very important to understand the inherent relationship between the geometric shape of energetic mole-cules and their crystal properties for the better design of low sensitivity high energetic materials(LSHEs).This study used neutral CHNO molecules containing nitro from the Cambridge Structural Database as samples.Hypothesis testing methods(including Z-,t-,andχ2 tests)were employed to investigate the correlation between the geometric shape of molecules and their crystal den-sity,packing coefficient,and slipping ability.The study shows that among spherical,planar and linear molecules:spherical molecules have the highest crystal density and packing coefficient,but weaker slipping ability;planar molecules with high pla-narity achieve a crystal density comparable to spherical molecules by a high packing coefficient,while also exhibiting stronger crystal slipping ability,its confidence level of theχ2 test is close to 1;linear molecules perform less well than the former two.Though some crystals with high crystal density and packing coefficient do not have slipping ability,general speaking,the crystal density and packing coefficient of the crystals with slipping ability are higher than those without.Both Z-tests and t-tests indicate a confidence level exceeding 0.95,suggesting that designing crystal structures conducive to intermolecular-layer slipping is not contradictory to reduceing their sensitivity and increasing crystal density.Planar molecules have a higher crystal density than av-erage,and it is strongly associated with crystal slipping ability,making them the preferred choice for designing LSHEs.

关 键 词：分子形状 晶体密度 堆积系数 剪切滑移 低感高能材料 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O64[理学—物理化学]