第一性原理对Si_nMg(n=1～12)团簇结构、稳定性与电子性质的研究  

First principles study of the structure,stability and electronic properties of Si_nMg(n=1～12) clusters

作　　者：张帅[1] 仲志国[2] 李根全[1] 吕林霞[1] 

机构地区：[1]南阳师范学院物理与电子工程学院,南阳473061 [2]南阳师范学院分析测试中心,南阳473061

出　　处：《原子与分子物理学报》2013年第3期407-415,共9页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(10947020);河南省自然科学基金(112300410112)

摘　　要：运用密度泛函理论(DFT)的杂化密度泛函B3LYP方法,在6-311G基组水平上对SinMg(n=1～12)团簇进行了构型优化、频率分析与电子性质计算.同时讨论了团簇的平均结合能、能级间隙、二阶能量差分、自然电子布居、极化率.研究结果表明:SinMg(n=1～12)团簇的基态绝大多数为立体结构.n=1时,体系的基态为自旋三重度,n≥2时,则为单重态.镁原子的掺入使得主团簇的电子性质发生了明显的变化,掺杂使体系的平均结合能降低,能隙减小,化学硬度减小,电子亲和能增大.电子总是从Mg原子向Si原子转移.团簇中原子之间的成键相互作用随n的增大而增强,团簇的电子结构随n的增大而趋于紧凑.The geometrical structure, frequency and electronic properties of the Sin Mg （n = 1 - 12） clus- ters have been investigated by using density functional theory （DFT） approach at B3LYP 6-311G level. The stabilities of the ground state for SinMg（n= 1-12） clusters are analyzed by means of the binding energies, energy gaps, second difference in energy, polarizations and natural population. The results in- dicate that： The ground state of most clusters have three dimensional structures. When n= 1, the spin multiplicity of the ground state structures of the cluster is triplet while it is singlet from n≥2. The ground state electronic properties of the host clusters are changed obviously due to the encapsulation of Mg atom. The doping of Mg atom increases the electron affinities energy, but reduces the average bind- ing energy, energy gap of the host cluster, and hardness of chemical. Charges always transfer from Mg atom to Si atoms in all sized SinMg clusters. The bonding interaction between atoms in cluster increases with the increasing cluster size, electronic structure of clusters tends to compact with the increasing cluster size.

关 键 词：SinMg团簇 几何结构 密度泛函理论 电子性质 

分 类 号：O561.1[理学—原子与分子物理] O552.5[理学—物理]