Ti_n(n=2～7)团簇结构,稳定性和电荷分布关系的密度泛函研究

The relationship between structures,stability and electrons population of Ti_n (n = 2 -7):a DFT study

利用密度泛函理论中的B3LYP方法,选择LANL2DZ基组优化Ti_n(2～7)团簇得到各团簇的稳定结构,然后对稳定结构的束缚能及自然轨道进行分析.研究结果表明:Ti_n(n=2～7)团簇都依带帽的形式在前一个团簇的结构基础上加一个原子变化而来;通过自然轨道分析发现,团簇原子的轨道存在sp-d杂化,有大约一个电子从4s转移到了3d,原子之间亦存在电子转移,而且除Ti_7外,团簇键长由最外层4d轨道电子和3d轨道共同决定,在Ti_7中,团簇键长由3d轨道决定.

The density function theory B3LYP method with LANL2DZ basic sets is adopted to opt all possible geometrical structures of Ti_n(n=2～7)and to get the most stable structure.Then,the binding energy and Natural bond orbital(NBO)of Ti clusters are calculated and discussed.The results show that the sturcture of each of Ti_n clusters is obtained by capping one Ti atom to the Ti_(n-1).The Natural bond orbital analysis show that the 4s,4p,4d orbitals hybridizes with 3d orbital,and about one electron transfer from 4s orbital to 3d orbital.Moreover,the electrons also transfer between different atom.The results also indicate that the average bond length of clusters were determined by the 4d and 3d orbitals except Ti_7.But for Ti_7,the average bond length only depend on 3d orbital.