Mg_mB_n(m=1,2;n=1—4)团簇结构与性质的密度泛函理论研究  

Density functional theory study on the structure and properties of Mg_mB_n(m=1,2;n=1—4) clusters

作　　者：陈玉红[1] 张材荣[1] 马军[1] 

机构地区：[1]兰州理工大学理学院

出　　处：《物理学报》2006年第1期171-178,共8页Acta Physica Sinica

基　　金：甘肃省自然科学基金(批准号:ZS022-A25-016)资助的课题~~

摘　　要：用密度泛函理论(DFT)的杂化密度泛函B3LYP方法在6-31G*基组水平上对MgmBn(m=1,2;n=1-4)团簇各种可能的构型进行几何结构优化,预测了各团簇的最稳定结构.并对最稳定结构的振动特性、电离势、成键特性、极化率和超极化率等性质进行了理论研究.结果表明,团簇的最稳定结构大多是平面结构,团簇的稳定结构中通常是几个呈负电性的B原子形成一个负电中心,而其他B原子和Mg原子通常处在端位,且显正电性;团簇中通常是B-B键和B-Mg键共存,极少出现Mg-Mg键,计算得到的B-B键键长在0·153—0·182nm之间,B-Mg键键长在0·221—0·231nm之间.Possible geometrical structures and relative stability of MgmBn （ m = 1,2 ; n = 1-4） clusters are studied by using the hybrid density functional theory（B3LYP） with 6-31G^＊ basis sets. For the most stable isomers of MgmBn （ m = 1,2; n = 1-4） clusters, the electronic structure, vibrational properties, bond properties, ionization potential, polarizability and hyperpolarizability are analyzed. The calculated results show that most of the optimized MgmBn （ m = 1,2; n = 1-4） clusters have planar structure, the B-B and B-Mg bonds are coexisting in the cluster, but the Mg-Mg bonds are infrequent in the clusters. The bond length of B-B is about 0. 153-0. 182nm and that of Mg-B is 0.221-0.231nm. The outcome of population analysis suggests that there is an electronegative center in the cluster, the other B and Mg atoms with positive charge are located at apexes of the duster.

关 键 词：MgmBn(m=1 2 n=1—4)团簇 密度泛函理论 结构与性质 

分 类 号：O511.4[理学—低温物理]