Au_(n-2)Ni_2(n=3-7)团簇的第一原理研究(英文)

Study on First Principle of Au_(n-2)Ni_2(n=3-7) Clusters

用基于密度泛函理论的第一原理方法,系统研究了合金团簇Aun-2Ni2(n=3-7)可能的稳定结构和最低能量异构体的相对稳定性,确定了系列低能量异构体,部分异构体的电子态具有较高的自旋多重性,比较研究了混合团簇与纯Aun团簇的稳定性。结果表明:Au-Ni原子间相互作用较强,这改善了混合团簇的稳定性,这种影响随团簇体积的增大而减小;混合团簇的能级间隙存在奇-偶振荡。

The first-principle method based on density-functional theory was used to investigate the geometries of the lowest-lying isomers of Aun-2Ni2（n=3-7） clusters.Several low-lying isomers were determined,and many of them in electronic configurations had a high spin multiplicity.The stability trend of Ni-doped Aun clusters was compared to that of pure Aun clusters.The results show that the gold–nickel interaction is strong enough to improve the cluster stability,and indicate that the larger the Aun cluster is,smaller the distortions by the two Ni atoms substitution are.It is observed that an odd-even alteration of the HOMO–LUMO gaps with the even numbered clusters is relatively more stable than the neighbouring odd-numbered ones.