伦敦色散力校正对含能分子晶体结构和弹性力学性能的影响  

Effect of London Dispersion Interaction on the Atomic Structure and Elastic Properties of Energetic Molecule Crystals

作　　者：李怡薇 范晓静 魏巍 韩旭辉 何春林 胡涛[2] 邵自强[1] 陈攀 LI Yi-wei;FAN Xiao-jing;WEI Wei;HAN Xu-hui;HE Chun-lin;HU Tao;SHAO Zi-qiang;CHEN Pan(School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China;School of Materials Science and Engineering,Shanghai University,Shanghai 200444,China)

机构地区：[1]北京理工大学材料学院,北京100081 [2]上海大学材料科学与工程学院,上海200444

出　　处：《火炸药学报》2023年第5期399-410,I0009,共13页Chinese Journal of Explosives & Propellants

摘　　要：基于密度泛函理论,通过调控不同色散校正方法,估算了六硝基六氮杂异伍兹烷(γ-CL-20)、三氨基三硝基苯(TATB)和环四亚甲基四硝胺(HMX)3种含能分子晶体间的非共价键相互作用,计算了其弹性张量,并考察了色散校正相互作用对HMX弹性张量的影响。结果表明,在所有晶体中,分子间伦敦色散能均大于分子间其他相互作用力,从而主导分子的排列堆积和结构稳定性;TATB分子中的平面氢键使结构具有明显的各向异性,从而导致弹性张量也呈现明显的各向异性,γ-CL-20和HMX结构和弹性张量的各向异性程度较低;取消色散校正会导致HMX弹性常数减小超过65%,证明当含能分子中没有氢键时色散校正能对弹性张量贡献巨大;弹性常数的相对大小可以定性反映出分子感度的相对高低,含能分子晶体弹性常数的理论值和实验值基本一致,对含能材料的结构和力学性能关系的理解具有重要意义。The non-covalent interactions and elastic tensors of hexanitrohexazaza-isowurtzitane(γ-CL-20),triamino-trinitrobenzene(TATB)and cyclotetramethylene tetranitramine(HMX)were calculated based on density functional theory(DFT)by adjusting different dispersion correction methods.The effect of dispersion correction interactions on the elastic tensor of HMX was investigated.The results show that the intermolecular London dispersion interaction is higher than the other intermolecular interaction for all crystals,dominating the tight stacking and structural stability.The planar hydrogen bonds in TATB molecules result in significant anisotropy in the structure,which results in significant anisotropy in the elastic tensor,while bothγ-CL-20 and HMX show relatively minor anisotropic features.The removal of the dispersion correction leads to a significant reduction of elastic constants(more than 65%)for HMX,proving that the dispersion correction makes a significant contribution to the elastic tensor of crystals when there is no hydrogen bonds in energetic molecules.The relative size of the elastic constants can qualitatively reflect the relative level of molecular sensitivity.The theoretical and experimental values of the elastic constants of energetic molecule crystals are basically consistent,which is important for the understanding of the relationship between the structure and mechanical properties of energetic materials.

关 键 词：量子化学 含能分子晶体 密度泛函理论 分子间相互作用 伦敦色散力校正 色散校正能 

分 类 号：TJ55[兵器科学与技术—军事化学与烟火技术] O641.12[理学—物理化学]