B_4^+分子的稳定构型和电子结构特征

Stable Configuration of B_4^+ Molecule and Structure of Electron

在QCISD/6 3 1 1G 水平上研究了B+ 4 分子的各种稳定构型 .首先通过从头计算优化出可能的稳定构型 ,再通过振动频率的计算判断所得构型是局部极小或鞍点 .同时讨论了Jahn Teller效应 .通过比较发现从头计算得到的各种构型与群论的结果一致 ,并得出一些文献中报道的构型实际上是鞍点 .

An ab initio study is made of the Jahn Teller distortion of the B + 4 molecule using quadratic configuration interaction with all single and double substitutions (QCISD) and 6 311G * basis set. For this cation, the D 2h (rectangle and rhombus), D 4h , C 2v (planar and non planar), D ∞h structure are full optimized and analyzed using energies, bond lengths and angles, harmonic frequencies and group theory. The present results predict a new stationary point structure of B + 4 cluster, i.e., C 2v configuration (non planar) for the first time. At the same time, it is pointed out that the rectangle and square structures are not minima but saddle points. It is found that there are the Jahn Teller distortions in both B + 4 (T d ) and B + 4 (D 4h ) geometries, and the symmetries of the distortions are in agreement with the results from resolution of group representations. The most stable configuration of B + 4 is D 2h (rhombus). Based on this, the dissociation energies are also computed and compared with other theoretical and experimental work.