密度泛函方法研究NiSin(n=1～6)团簇

目的确定NiSin（n=1-6）团簇的稳定几何结构、Mulliken原子净布居、重叠布居、自然布居、自然电子组态、总能及分裂能，初步探讨Ni-Si成键机制。方法运用杂化密度泛函理论，在（U）B3LYP／LanL2DZ水平上对NiSin（n=1-6）团簇进行计算。结果得到NiSin（n=1-6）团簇的一系列稳定几何结构，以及Mulliken原子净布居、重叠布居、自然布居、自然电子组态、总能及分裂能等。结论计算结果表明在稳定的NiSin（n=1-6）团簇中，电子从Ni向Si转移，并且Ni—Si重叠布局为正，增强团簇的稳定性，分裂能D（n，n-1）中D（2，1）最大，说明NiSi2是NiSin（n=1-6）中最稳定的团簇结构。

A density functional investigation of NiSin ( n = 1 ～ 6) clusters

Aim To find out the ground state structures of NiSi_n(n=1~6) clusters and its natural population,natural electron configuration,Mulliken population,overlap population,total energy,fragmentation energies and bonding mechanism in accidence.Methods Density functional method computation at the B3LYP/ LanL2DZ level.Results A series of stable geometries and electronic configurations were found,along with natural population,natural electron configuration,Mulliken population,overlap population,total energy,fragmentation energies.Conclusion Theoretical results show that the charges of the lowest-lying NiSi_n(n=1~6) isomers are transferred mainly from Ni atoms to Si atoms,and Ni-Si overlap population are positive,which enhances the stability of clusters.Based upon our theoretical results of fragmentation energy,D(2,1) turns out to be the largest one among the D(n,n-1),which is corresponding to the most stable NiSi_2 of NiSi_n(n=1~6) clusters.