密度泛函理论对Cd_nTe_n(1≤n≤12)团簇结构与性质的研究

The structures and properties of Cd_nTe_n(1≤n≤12) clusters have been studied by using density-functional theory

采用基于密度泛函理论的DMol 3软件包对CdnTen(1≤n≤12)团簇的几何结构进行优化,并对其能量、频率以及电子性质进行模拟分析.结果表明,团簇CdnTen(1≤n≤12)与团簇CdnSen(1≤n≤12)具有相似的最低能量结构:当n=1～3时,团簇的最低能量结构是平面结构;当n=4～12时,团簇的最低能量结构可以看成是由Cd2Te2和Cd3Te3团簇的最低能量结构组成的三维笼状结构;当n=12时,Cd12Te12团簇的最低能量结构为一个完美的球壳.随着团簇尺寸的增大,转移的电荷逐渐增加,转移的电荷量有达到块体中电荷值的趋势.团簇的总能量二阶有限差分,平均结合能以及能隙都显示团簇的幻数为Cd3Te3,Cd6Te6和Cd9Te9.

The lowest-ener by using density-functiona gy structures and properties of Cdn Ten（1≤n≤12） clusters have been studied 1 theory simulating package DMoP. The lowest-energy structures of Cdn Ten （1≤n≤12） clusters have the same as Cdn Sen（1≤n≤12） clusters. Ring-like structures have been found to be the lowest-energy configurations in the case of the smaller calculated clusters at n= 2 and 3, and three dimensional spheroid configurations for the larger ones at n=4- 12. The three dimensional structures may be envisioned as being built from the Cd2Te2 and Cd3Te3 rings. Especially, the lowest-energy con- figuration of Cd12 Te12 cluster is a perfect spherical shell. As cluster size increase, the properties of Cd. Te, clusters trend to bulklike properties in Mulliken atomic charge. Calculations show that the magic numbers of Cdn Ten（1≤n≤12） clusters are Cd3Te3, Cd6Te6 and Cd9Te9.