RDX分子内振动能量重分配的动力学研究  

Dynamics Study of Intramolecular Vibrational Energy Redistribution in RDX Molecule

作　　者：张伶育 张继龙[1] 曲泽星 ZHANG Lingyu;ZHANG Jilong;QU Zexing(Institute of Theoretical Chemistry,College of Chemistry,Jilin University,Changchun 130023,China)

机构地区：[1]吉林大学化学学院,理论化学研究所,长春130023

出　　处：《高等学校化学学报》2022年第10期283-289,共7页Chemical Journal of Chinese Universities

基　　金：2020基础加强计划项目(批准号:GFJQ2126-007)资助.

摘　　要：基于从头算分子动力学(Born-oppenheimer moleculardynamics,BOMD)模拟,构建了环硝胺六氢-1,3,5-三硝基-1,3,5-三嗪(RDX)单分子不同振动模式之间的耦合矩阵,并计算了在不同加载能量下从低频振动模式到高频振动模式的最优能量传输路径.结果表明,RDX单分子中—NNO_(2)基团更有利于能量局域化,振动模式v_(3)和v_(4)在从低频振动模式到高频振动模式的能量传输过程中扮演着重要角色.通过对v_(3)和v_(4)两个振动模式的进一步分析发现,加载能量的不同会导致RDX单分子能量传输路径的不同.当加载能量较低时,RDX单分子倾向于从低频振动模式到中频振动模式再到高频振动模式的能量传输路径;当加载能量较高时,能量更倾向于从低频振动模式直接传输到高频振动模式上.揭示了RDX分子内振动耦合能量转移的微观机制,为进一步探索RDX将“机械能”转化为“化学能”的微观过程提供了理论基础.In this paper,based on the Born-oppenheimer molecular dynamics(BOMD)simulations,the coupling matrix between different vibrational modes of cyclotrimethylene trinitramine(RDX)single molecule was constructed,and the optimal energy transfer pathways from low-frequency vibrational mode to high-frequency vibrational mode with different initiation energies were obtained.The results showed that the—NNO_(2) group in RDX single molecule was more favorable for energy localization,while vibrational mode v_(3) and vibrational mode v_(4) played an important role in the energy transfer process from low-frequency vibrational mode to high-frequency vibrational mode.The further analysis for the two vibrational modes of v_(3) and v_(4) suggested that different initiation energy could lead to different energy transfer pathways for RDX single molecule.With the lower initiation energy,the RDX single molecule tended to follow the energy transfer pathway as,low-frequency vibrational mode→medium-frequency vibrational mode→high-frequency vibrational mode.With the higher initiation energy,the energy tended to transfer from the low-frequency vibrational mode to the high-frequency vibrational mode.This work reveals the detail mechanism of the intramolecular vibrational energy redistribution in single RDX molecule,and can be further applied in the investiga⁃tion of other energy transfer process.

关 键 词：环硝胺六氢-1 3 5-三硝基-1 3 5-三嗪 分子内振动能量重分配 能量转移 从头算分子动力学 

分 类 号：O641[理学—物理化学]