稀土掺杂硼团簇REBn-(RE=La,Sc;n=6,8)的几何及电子结构
Geometry and electronic structures of rare earth-doped boron-based clusters REBn-(RE=La,Sc;n=6,8)
陈子俊 1李慧芳 1谢圳明 1张勇航 2郑浩 2姜凯乐 2张博 2张家铭 2王怀谦3
作者信息
- 1. 华侨大学工学院,泉州 362021
- 2. 华侨大学信息科学与工程学院,厦门 361021
- 3. 华侨大学工学院,泉州 362021;华侨大学信息科学与工程学院,厦门 361021
- 折叠
摘要
稀土掺杂硼团簇因其特殊的光学,电学和磁学性质受到广泛关注.本文采用人工蜂群算法结合密度泛函理论,在PBE0/RE/SDD//B/6-311+G*水平下研究了稀土掺杂阴离子硼团簇REB-(RE=La,Sc;n=6,8)的几何结构、电子性质、稳定性和芳香性.计算结果表明,阴离子REBn-(RE=La,Sc;n=6)的基态结构具有C2对称性,掺杂的镧系原子位于顶部中心形成"船形"结构.通过与实验光电子能谱的比较,证实LaB8-的基态结构类似于三维的"筝形"结构,而ScB8-的基态结构则是Sc原子位于"伞柄"处形成的具有C7v对称性的"伞状"结构.B—B之间存在通过共享电子对的相互作用,而RE—B之间的电子定域性不如B—B之间的电子定域性.模拟得出的光电子能谱峰值位置与实验结果的吻合度较高,充分证实了研究获取的全局能量最低结构与实验观测结构的一致性.LaB6-和ScB6-的最低能量结构均为σ-π双芳香簇,表现出明显的芳香性.此外,分别计算了 REBn-(RE=La,Sc;n=6,8)的总态密度,以及RE原子和硼簇的局部态密度,并对其轨道能级密度进行了评估.开壳层的ScB8-态密度谱呈现出自旋极化现象,这表明其作为基元可以组装成具有磁性的纳米材料.这些对稀土掺杂硼团簇的研究有助于深入理解纳米材料的结构和性质演变规律,为设计具有实际价值的纳米材料提供了重要的理论支持.
Abstract
Rare earth doped boron clusters have attracted much attention due to their special optical,electrical and magnetic properties.The geometric structures,stability,electronic properties and aromaticity of negative rare earth doped boron clusters REBn-(RE=La,Sc;n=6,8)are investigated with the artificial bee colony algorithm combined with density functional theory calculations at the PBE0/RE/SDD//B/6-311+G*level of theory.Calculations show that the ground state structures of REB-(RE=La,Sc;n=6,8)are all of C2 symmetry,and the doped lanthanide atom is located in a"boat-shaped"structure at the top center.By comparing with the experimental photoelectron spectra,it is confirmed that the ground state structure of LaB8-is a"zither-like"three-dimensional structure,and the ground state structure of ScB8-is an"umbrella"structure with C7v symmetry formed by the scandium atom at the"umbrella handle".The electron localization between RE—B is not as good as that between B—B.The simulated photoelectron spectra have similar spectral characteristics to the experimental results.The lowest energy structures of LaB6-and ScB6-are σ-π double aromatic clusters,and the structures exhibit aromaticity.The density of states of low-energy isomers shows that the open shell ScB8-density of states spectrum exhibits spin polarization phenomenon,which is expected to assemble magnetic material components.These studies contribute to understanding the evolution of structure and properties of nanomaterials,and provide important theoretical support for designing nanomaterials with practical value.
关键词
密度泛函理论/稀土掺杂团簇/结构优化/芳香性Key words
density functional theory/rare earth doped clusters/structural optimization/aromaticity引用本文复制引用
基金项目
福建省自然科学基金(2023J01141)
厦门市自然科学基金(3502Z202373051)
出版年
2024
国家科技期刊平台
NSTL
万方数据