文献类型：期刊文献

中文题名：NiMgn(n=1-12)团簇的第一性原理研究

英文题名：First-principles study of the NiMg_n(n=1—12) clusters

作者：姚建刚[1];王献伟[1];王渊旭[1];井群[1];罗有华[1,2]

机构：[1]河南大学计算材料科学研究所,河南大学物理与电子学院,开封475004;[2]华东理工大学理学院,上海200237

年份：2008

卷号：57

期号：7

起止页码：4166

中文期刊名：物理学报

外文期刊名：Acta Physica Sinica

收录：CSTPCD;;EI(收录号：20083111422678);Scopus;北大核心:【北大核心2004】；CSCD:【CSCD2011_2012】；

基金：河南大学自然科学基金(批准号:07ZRZD005)资助的课题~~

语种：中文

中文关键词：NiMgn团簇;几何结构;稳定性;化学活性

外文关键词：NiMgn, geometrical structures, stability, chemical activity

摘要：采用基于密度泛函理论(DFT)中的广义梯度近似(GGA),在考虑自旋多重度的情况下,对NiMgn(n=1—12)团簇进行了构型优化,频率分析和电子性质计算.结果表明:n=1,2时,体系的基态为自旋三重态,n≥3时,为单重态;Ni原子掺杂使主团簇结构发生了明显变化.n≤8时,三角双锥,四角双锥结构主导着NiMgn基态团簇的生长行为;n在9—12之间时,主团簇Mgn+1(n=1—12)的基于三棱柱构型的基态演化行为发生了一定程度的改变;n≥6时,Ni原子陷入了主团簇内部;掺杂使体系的平均结合能增大,能隙减小;n=4,6,10是团簇的幻数;不同尺寸团簇的s,p,d轨道杂化中,Ni原子3d,4p成分所起作用不同;NiMg6基态结构具有很高的对称性(Oh),很好的稳定性和化学活性,能隙仅为0.25eV.
The geometrical structure, frequency and electronic properties of the NiMgn （ n = 1-12） clusters have been studied with the generalized gradient approximation （GGA） based on the density functional theory （DFT） with the consideration of spin multiplicity. The results indicate that： when n is 1 or 2, the spin multiplicity of the ground state structures of the clusters is triplet while it is singlet from n ≥ 3. The ground state structures of the host clusters are changed obviously due to the encapsulation of Ni atom for n ≤ 8, the growth patterns of the ground state structures of the NiMgn clusters are dominated by the trigonal bipyramidal, as well as the octahedron structures. The evolution behaviors of the ground state structures based on the trigonal prism of the host clusters are partly modified from n 1〉 9. The Ni atom completely falls into the center of the host clusters as n ≥ 6. The doping of Ni atoms increases the average binding energy, but reduces the energy gap of the host clusters, n = 4, 6 and 10 are the magic numbers. The 3d and 4p orbitals of the Ni atom for different sized clusters play distinct roles in the s-p- d orbital hybridization. The NiMg6 cluster with higher symmetry Oh not only possesses improved stability, but also has the smallest energy gap （just about 0.25 eV） of all of the NiMgn clusters.