CdSe和HgTe团簇基态性质的第一性原理计算  

FIRST-PRINCIPLES CALCULATION ON THE GROUND STATE PROPERTIES OF CdSe AND HgTe CLUSTERS

作　　者：罗强[1] 王新强[2] 何焕典[3] 邹其徽[1] 

机构地区：[1]西南石油大学理学院,成都610500 [2]重庆大学数理学院,重庆400044 [3]湛江师范学院,广西湛江524048

出　　处：《硅酸盐学报》2008年第8期1159-1162,1167,共5页Journal of The Chinese Ceramic Society

基　　金：西南石油大学自然科学基金资助项目

摘　　要：基于密度泛函理论的第一性原理方法,在广义梯度近似下,计算了团簇(CdSe)n和(HgTe)n(原子数n=1～7)的结构和电子性质,以及团簇(CdSe)n和(HgTe)n的最高占据轨道和最低未占据轨道的能隙、结合能。结果表明:团簇(CdSe)n能隙与结合能均在n=5时出现了极小值,n=4时出现极大值;团簇(HgTe)n只是在n=4时出现了较大能隙,没有出现极小值。能隙随结合能变化而变化。比较了团簇(CdSe)n和(HgTe)n(n=4,5和7)的基态结构,发现同种结构对称性的不同团簇对应着不同的稳定性,这是导致块体材料CdSe形成闪锌矿结构和HgTe形成纤锌矿结构的原因。Using the first principles method, which is based on the density function theory （DFT）, the structures and electronic properties of （CdSe）n and （HgTe）n （n=1-7） clusters, and their energy gaps of the highest occupied molecular orbital and the lowest unoccupied molecular orbital and binding energies were calculated with the generalized gradient approximation. The results show that the （CdSe）n cluster with n=5 has the lowest energy gaps and binding energy, （HgTe）n cluster with n=4 has the highest energy gaps and binding energy. The energy gaps of the clusters change with the change of binding energy. The differences between geometrical structures of the ground state of （CdSe）n and （HgTe）n clusters （n=4, 5 and 7） were analyzed, and it was found that the clusters with the same structures on the symmetry have different stability. The results provide a valuable reference for understanding the cause for the formation of different structures for the materials, i.e., with zincblende structure for CdSe crystal and wurtzite structure for HgTe crystal.

关 键 词：硒化镉 碲化汞 团簇 结合能 能隙 基态结构 

分 类 号：O561[理学—原子与分子物理]