AgGen(n=1～17)团簇:几何结构,稳定性和电子性质

摘要

Germanium cluster doped with an Ag atom has been systematically investigated by using density functional theory approach at B3LYP/LanL2DZ level. Different growth patterns appear between small-sized (n = 1～11) Ag-doped germanium clusters and relative larger-sized (n=12～17) Ag-doped germanium clusters. For the most stable structures of AgGen ( n = 12～17) clusters, the Ag atom would be completely surrounded by Ge atoms to form Ag-encapsulated Gen cages. According to the calculated fragmentation energy and the second-order difference of the total energy,we predict that the magic number of AgGen (n=1～17) clusters should be 5,10,12 and 15. Mulliken population analysis shows that the direction of charge transfer depends on the size of the cluster and the doped transition metal. We research dynamical stability of cluster by analyzing vibrational spectra. The obvious infrared and Raman spectra characters can be used to distinguish the structure from experiments.%利用密度泛函理论的B3LYP/LanL2DZ方法,对AgGen(n=1～17)团簇进行了系统的研究,较小的AgGen(n=1～11)和相对较大的AgGen(n=12～17)团簇出现了不同的生长方式.从n=12开始,形成了银原子被锗原子完全包围的笼状结构.根据AgGen团簇的分裂能和二阶能量差分,预测了AgGen(n=1～17)团簇的幻数为n=5、10、12和15.Mulliken电荷布局分析显示电荷转移的方向和团簇的大小与掺杂的金属种类有关.通过分析振动光谱,研究了团簇的动态稳定性,在实验中明显的红外谱和拉曼谱能被用来区别团簇结构.