摘要
利用从头算梯度修正密度泛函理论 ,我们在B3LYP/ 6 - 31G(d ,p)水平上 ,计算了高能炸药黑索金 (RDX)及其热解中间产物C3 H6N5O4和NO2 等的电子结构、能量、键级和一些热力学性质 ,并在此基础上 ,计算了键离解能和反应速率常数。此外 ,我们还分别从键级和键离解能角度 ,讨论了RDX的热解机理 。
We calculate the electronic structures, energies, bond orders, and thermochemistries of the gas unimolecule hexahydro-1, 3, 5-trinitro-1, 3, 5-triazine (RDX) and its intermediate products formed during its decomposition process using first principles gradient corrected density functional theory (DFT) at the B3LYP/6-31G(d, p) level. With the information obtained, we also consider the bond dissociation energy and rate constant of reaction and further investigate the decomposition of RDX from two aspects of bond order and bond dissociation energy. Results show that the dominant reaction channel is the N-NO_2 bond rupture, which has the weakest Mulliken bond order and bond dissociation energy are 0.162?3 and 157.271?8?KJ/mol respectively. The calculated results are in agreement with experiments and demonstrate that it is simpler using bond order to determine the order of bond breaking than using the bond dissociation energy particularly for larger molecule such as RDX.
出处
《原子与分子物理学报》
CAS
CSCD
北大核心
2005年第1期105-109,共5页
Journal of Atomic and Molecular Physics
基金
TheprojectissupportedbytheNationalNaturalScienceFoundationofChinaandtheFoundationofChinaAcademyofEngineeringPhysicsunderGrantNo .1 0 376 0 2 1 .
关键词
黑索金
密度泛函理论
键级
键离解能
RDX, DFT, Geometries
Bond order
Bond dissociation energy
