掺钌硅原子簇的结构及其稳定性研究

采用密度泛函方法B3LYP/6311SDD方法系统研究了掺钌硅原子簇RuSin (n = 1-14) 的几何结构、稳定性以及电子性质。研究结果表明，当n 3时，RuSin的基态结构由平面结构转为三维的立体结构。随着硅原子数由1增长到14，RuSin原子簇中Ru原子的位置逐渐从原子簇表面转移到原子簇内部。当n = 12时，Ru原子完全陷入了原子簇结构中，形成一个以钌为中心的硅笼结构。自然键轨道分析表明RuSin(n = 2-14)的基态结构中都存在三中心键，证明了这些结构的稳定性。此外，RuSin (n = 1-14)原子簇各基态结构的平均结合能、二阶差分能、HOMO-LUMO能隙、电离势、电子亲和势等信息表明RuSi12的基态结构有着很高的稳定性。

Structures and Stabilities of the Ruthenium-Doped Silicon Clusters

The geometries, stabilities and electronic properties of the ruthenium-doped silicon clusters RuSin (n = 1-14) have been systematically investigated using density functional theory method at the B3LYP/6311SDD level. Our results show that the ground state structures of RuSin change from planar to three-dimensional for n 3. The equilibrium site of the Ru atom in RuSin gradually changes from convex, surface, to interior of the cluster as the number of Si atoms varying from 1 to 14. Starting from n = 12, the Ru atom completely falls into the center of the Sin frame, forming Ru-centered Sin cage-like structures. Three-centered bonds were calculated to ensure the stability of the ground state structure. Besides, the average binding energies, second order energy differences, HOMO-LUMO gaps, vertical ionization potentials, vertical electron affinities and charge transfers were also discussed for the lowest-lying RuSin (n = 1-14) isomers. According to a relatively large Eb and ?2E values, the RuSi12 cluster with Ru-centered perfect hexagonal prism structure has higher stability.