密度泛函方法研究NbSi_n(n=1～6)团簇

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

目的研究NbSin(n=1～6)团簇的几何构型及电子结构.方法采用密度泛函理论(DFT),在UB3LYP/LanL2DZ水平下用Gauss98程序对各构型进行几何优化和频率分析,同时考虑了电子的多重度.结果得到了一系列稳定的NbSin(n=1～6)团簇构型,并计算出了其键长(Nb-Si和Si-Si)、总能量、电子布居和分裂能.结论NbSin(n=1～6)团簇的立体结构比平面结构和直线结构更稳定;每一个n(n=1～6)值所对应最稳定结构中,Nb原子的电子Mulliken净布局和自然布局在Si原子数目小于3时为正值,其余为负值.

Aim To investigate the symmetry structure and electronic configuration of NbSi_n(n=1~6) clusters.Methods A density functional theory was used when the geometry optimization and frequencies analysis were performed by Gauss98 code under the UB3LYP/LanL2DZ level, considering the spin of electron. Results A serial stable NbSi_n(n=1~6) clusters are obtained with its symmetry structures, total energies, electronic populations and fragmentation energies. Conclusion The solid structures are more stable than the plane and line structures; the Mulliken atomic net population and nature population of Nb atom of the most stable structures in every n are positive when n≤2 and negative when 3≤n≤6.