掺铅锂小团簇的结构、稳定性和化学键研究

Study on structure, stability and chemical bonding of small Pb-doped Li clusters

摘要:

采用密度泛函理论的B3LYP方法，对锂原子用全电子6-311++g(d,p)基组，铅原子用sddall相对论有效实势基组研究了LinPb(n=7-9)二元团簇较低能量构型的几何结构，并讨论了能量最低的基态构型的化学键和稳定性. 研究表明掺入的铅原子与锂原子之间形成的化学键为共价键，并且成键的价电子对倾向于铅原子. Li8Pb二元团簇基态构型的最高占据分子轨道和最低未占据分子轨道之间的能隙比LinPb(n=7，9)二元团簇基态构型的大. 此外，基于对LinPb(n=7-9)二元团簇基态构型平均原子化能，垂直电离能，垂直电子亲和能的计算分析，得出Li8Pb二元团簇的基态构型最稳定.

Abstract:

The geometrical structures of lower energies LinPb(n=7-9) binary clusters have been investigated through B3LYP method of density functional theory where the basis set includes the all electrons 6-311++g(d, p) to lithium atom and relativistic effective core potentials to lead atom. Simultaneously, we have been studied the chemical bond and stability of the lowest energy structures. The investigation suggest that the chemical bond between the impurity lead atom and lithium atoms is covalent bond, bonding valence electron-pair tend to lead atom. The energy gap between the highest occupied molecular orbital(HOMO) and the lowest unoccupied molecular orbital(LUMO) of Li8Pb cluster’s ground state configuration is larger than LinPb(n=7 and 9) clusters’. In addition, based on the atomization energy per atom, vertical ionization energy and vertical electron affinity calculations, Li8Pb cluster’s ground state configuration is the most stable one.