密度泛函理论研究CeSin(n = 1~8)的结构与性质
Study on the Structures and Properties of CeSin (n = 1 - 8) with Density Functional Theory

作者: 张晓杰 , 杨桔材 :内蒙古工业大学环境科学与工程系,呼和浩特;

关键词: CeSin基态结构磁性稳定性CeSin Ground State Structures Magnetic Moments Stabilities

摘要:
采用B3LYP结合稀土元素小核ECP28MWB基组,研究了CeSin (n = 1~8)体系的几何构型,报导了其基态结构,分析了其基态的相对稳定性、磁性、电荷分布、偶极矩等性质。研究结果表明,CeSin基态可以看作是Ce取代Sin+1上的一个Si原子所获得,除了CeSi基态是5重态之外,其它物质是3重态;在CeSin中,Ce原子是电子供体,Sin团簇是电子受体,Ce原子的4f电子变化不大,主要失去6s电子,部分进入5d轨道,部分进入Sin团簇;分裂能表明CeSi2、CeSi5和CeSi8相对比较稳定,而CeSi4和CeSi7相对稳定性较差;CeSi的偶极矩最小,CeSi8的偶极矩最大;CeSin团簇的磁矩主要由掺杂的Ce原子所提供。

Abstract: The geometries of CeSin (n = 1 - 8) were studied by means of the B3LYP method in combination with small core ECP28MWB basis sets of the rare earth metals. The ground state structures of CeSin (n = 1 - 8) clusters were reported. The properties of relative stabilities, magnetic moments, charge distributions and dipole moments were analyzed. The results revealed that the ground state structures of CeSin (n = 1 - 8) can be regarded as being derived from the lowest-energy structure of Sin+1 by replacing a Si atom with a Ce atom. The ground state of all of these is triplet with the exception of CeSi, which is quintet. The Ce atom is electron donor and the Sin cluster is electron acceptor. The 4f electrons of Ce atom have little changes. The main change is that the 6s electrons of Ce atom transfer to 5d orbitals and Sin clusters. Dissociation energies showed that CeSi2, CeSi5 and CeSi8 are more stable, and CeSi4 and CeSi7 are less stable. The dipole moments of CeSi are maximal and the dipole moments of CeSi8 are minimal. The majority of total magnetic moments of CeSin are contributed by Ce atom.

文章引用: 张晓杰 , 杨桔材 (2014) 密度泛函理论研究CeSin(n = 1~8)的结构与性质。 物理化学进展, 3, 25-32. doi: 10.12677/JAPC.2014.34004

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