Au12M(M=Na,Mg,Al,Si,P,S,Cl)团簇的结构、稳定性和电子性质

摘要

The geometries,stabilities,and electronic properties of Au12M (M=Na,Mg,Al,Si,P,S,Cl)clusters were systematically investigated by using first-principles calculations based on density functional theory (DFT).For each cluster,the average binding energy,the embedding energy,the vertical ionization potential,the energy gap between the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO),the natural charge population analysis,and the natural bond orbital analysis (NBO) were calculated.The lowest-energy structures of Au12M (M=Na,Mg,Al)clusters are cages with M encapsulated in the center,while structures of Au12M (M=Si,P,S,Cl) clusters are pyramidal with M at the apex.The Au12S cluster,having the full closed-shells,is the most stable.Furthermore,from the natural population analysis,it follows that charges transfer from Au to M in all the clusters.The NBO and HOMO analyses reveal that hybridization occurs between the Au s-d orbitals and the M p orbitals.%采用基于密度泛函理论的第一性原理方法系统地研究了Au12M (M=Na,Mg,Al,Si,P,S,Cl)团簇的结构、稳定性和电子性质.对团簇的平均结合能、镶嵌能、垂直离化势、最高占据分子轨道(HOMO)和最低未占据分子轨道(LUMO)的能级差、电荷布居分析、自然键轨道(NBO)进行了计算和讨论.对于Au12M(M=Na,Mg,Al)团簇,它们形成了内含M原子的最稳定的笼状结构.然而对于Au12M (M=Si,P,S,Cl)团簇,它们却形成了以M元素为顶点的稳定锥形结构.在这些团簇中发现Au12S团簇相对是最稳定的,这是由于Au12S团簇形成了稳定的满壳层的电子结构.自然电荷布居分析表明:对于所有的Au12M (M=Na,Mg,Al,Si,P,S,Cl)团簇电荷总是从Au原子转向M原子.自然键轨道和HOMO分析表明Au12M团簇中发生了Au原子的s-d轨道和M原子的p轨道间的杂化现象.