摘要采用密度泛函理论（DFT）中的B3LYP方法和6-31G(d)基组，对乙硼烷（B2H6）进行了构型优化和频率计算，得到了B2H6的稳定构型，再根据能量高低确定其基态结构， 然后在其基态结构的基础上进行一系列性质的相关计算。主要结论如下：86718

1。通过查阅文献，构建出B2H6的建构模型，并进行优化计算，得到了B2H6的基态构型，确定了其具有D2H对称性；

2。对基态构型进行稳定性和化学活性分析，其平均结合能为-53。204eV，能隙为0。297eV，表明其稳定性差，化学活性强；

3。极化率分析：B2H6极化率张量的平均值小于B5H5,原子间成键作用和离域效应相对较弱，B2H6相对不稳定；

4。NBO分析：B原子的NBO电荷分布主要集中在2p轨道，B2H6的电荷转移即s、p轨道杂化不仅发生在B原子内部，而在B原子之间也有杂化现象；

5。通过对B2H6的红外光谱分析可知，最强的振动峰位于波数为1750cm-1处，该处的振动模式为呼吸振动。其他振动峰值波段在1000~2800cm-1范围内，振动方式为伸缩振动。对拉曼光谱分析可知最强峰的振动频率大概在2650cm-1左右，拉曼光谱的活性为127A4•amu-1。

毕业论文关键词：B2H6分子；结构与性能；密度泛函理论

Abstract  Density functional theory (DFT) B3LYP method and the 6-31G (d) basis set of diborane (B2H6) were geometry optimization and frequency calculations obtained B2H6 stable configuration, according to the energy level determine the ground state structure, and then a series of related calculations on the basis of the nature of its ground state structure。 The main conclusions are as follows：

  1。 Through literature, the construction of the model constructed B2H6, and optimization, has been B2H6 ground state configuration, determine that it has symmetry D2H;

  2。 The ground state configuration stability and chemical activity analysis, the average binding energy -53。204eV, energy gap 0。297eV, showed its poor stability, chemical activity;

  3。 Susceptibility analysis: Mean B2H6 polarizability tensor less than B5H5, interatomic bonding effect and relatively weak delocalization, B2H6 relatively unstable。

  4。NBO analysis: NBO charge distribution B atoms mainly in 2p orbital charge transfer B2H6 ie s, p orbital hybridization occurs not only inside the atom B, and between B atoms are also hybrid phenomenon。

  5。By B2H6 of infrared spectroscopic analysis shows that the strongest vibration peak at the wave number of 1750cm-1 Service, which is the vibration of respiratory vibration mode。 Other vibration band peak in the range of 1000 ~ 2800cm-1, the vibration mode of stretching vibration。 Raman spectroscopy shows that the vibration frequency of the most intense peak at about 2650cm-1 about Raman spectrum activity 127A4 • amu-1

Keywords:  B2H6molecular ; structure and property ;density functional theory     

目  录

第一章 绪论 1

1。1 引言 1

1。2 团簇的概念 2

1。3 本论文研究内容和意义 2

      1。3。1 本论文研究内容 2

      1。3。2 本论文研究意义 3

第二章 理论和计算方法 4

2。1 量子化学 4

2。2 量子化学的应用 5

2。3 密度泛函理论的简介 6

2。4  密度泛函理论的应用