Cu_n、Ag_n、Au_n（n＝2，3，4）原子簇结构的理论分析

Theoretical Analyses of Clusters Cu_n,Ag_n,Au_n(n=2,3,4)

在应用ＤＶ－Ｘａ自洽场方法研究Ｃｕｎ、Ａｇｎ、Ａｕｎ原子簇电子结构基础上，分析了原子簇中原子轨道间的相互作用及其大小随几何构型的变化，并讨论了原子簇的Ｘａ总能量与原子簇几何构型的关系。采用单、双过渡态理论方法分别计算原子簇分子轨道的电离能和分子轨道的电子跃迁能，结果表明Ａｇｎ的电离能计算值与实验值符合较好，而Ａｕｎ原子簇则有一定偏差，这可能是由Ａｕｎ的较大相对论效应引起的，Ａｇ４的电子跃迁能与实验值亦符合较好。

Atomic orbital interactions of clusters Cun, Agn,Aun(n=2,3,4) were analyzed with DV-Xa method The results showed that the interactions vary with the geometry of clusters.The ionization potentials of clusters are investigated by using the transition-state procedure,and the calculating results for Agn are in agreement with the experimental values,however,there are some deviations between them for Aun,due to the larger relativistic effect of Aun.