GaSi_n(n=1-6)团簇结构和稳定性的第一性原理研究  

First-principles study on geometries and stabilities of small GaSi_n( n = 1-6) clusters

作　　者：杨阿平[1] 温俊青[1] 郭平[2] 

机构地区：[1]西安石油大学理学院,西安710065 [2]西北大学物理学院,西安710069

出　　处：《原子与分子物理学报》2017年第1期61-70,共10页Journal of Atomic and Molecular Physics

基　　金：陕西省教育厅专项科研计划项目(2013JK0630)

摘　　要：采用密度泛函理论(DFT),在B3LYP/6-311+G(d)水平下研究了GaSi_n(n=1-6)团簇的几何构型、电子性质、稳定性和振动特性.研究结果表明:GaSi_n(n=1-6)团簇基态结构基本保持了纯硅团簇的结构框架,Ga原子往往被吸附在Sin团簇的表面上.布局分析显示电子由Ga原子向Sin框架转移.平均束缚能和分裂能表明GaSi_3和GaSi_5团簇相对其他团簇具有较强的稳定性.振动特性研究表明:GaSi_n(n=1-6)团簇的IR活性最强振动模式主要是Ga原子与Sin结构之间的相对振动.极化率的研究表明,随着Si原子数的增多,GaSi_n团簇的非线形光学效应逐渐增强,更容易被外场极化.The equilibrium geometries, electronic configurations, stabilities and vibrational properties of GaSi, （ n = 1 -6） clusters have been investigated at the B3LYP/6 -311 ＋ G（d） level available in Gaussian03 program. Our calculations reveal that the most stable structure of GaSin （ n = 1 - 6） clusters basically keeps the analogous frameworks as the pure Sin＋1 clusters, and the doped Ga atom is always adsorbed at a surface site. For the most stable isomers, charge transfer is found to proceed from Ga atom to the Si, framework; both the binding and fragmentation energies suggest that GaSi3 and GaSi5 have stronger stability. By investigating the vibrational properties, we have found that the maximal IR active vibrational frequencies of GaSi, （ n = 1 - 6） clusters are attributed to the relative movements of the Ga atom and the Sin framework. With the increasing of Si atoms, GaSi. clusters will have stronger nonlinear optical effect and be easier to polarize by external electromagnetic field.

关 键 词：GaSin团簇 几何结构 稳定性 振动频率 

分 类 号：O561.1[理学—原子与分子物理]