高等学校化学学报

高等学校化学学报

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密度泛函理论在分子磁学中的应用——混合价三核锰配合物磁性的理论研究

任杰1,2, 王炳武1, 陈志达1, 徐光宪1   

    1. 分子科学国家实验室, 稀土材料化学及应用国家重点实验室, 北京大学化学与分子工程学院, 北京 100871;
    2. 河北科技大学理学院, 石家庄 050018
  • 收稿日期:2008-10-21 修回日期:1900-01-01 出版日期:2008-12-10 发布日期:2008-12-10
  • 通讯作者: 陈志达

Application of Density Functional Theory to Molecular Magnetism——Theoretical Study on Magnetic Properties of Mixed-valence Trinuclear Manganese Compounds

REN Jie1,2, WANG Bing-Wu1, CHEN Zhi-Da1*, XU Guang-Xian1   

    1. National Laboratory for Molecular Sciences, State Key Laboratory of Rare Earth Materials Chemistry and Applications, College of Chemistry and Molecular Engineering, Peking University, Beijing 100871, China;
    2. Hebei University of Science and Technology, College of Science, Shijiazhuang 050018, China
  • Received:2008-10-21 Revised:1900-01-01 Online:2008-12-10 Published:2008-12-10
  • Contact: CHEN Zhi-Da

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被引次数

20

摘要： 在对混合价化合物分类的基础上, 将双核耦合模型推广到三核磁耦合体系, 重点研究定域与离域两类混合价化合物的磁学性质. 以混合价三核锰为例, 应用密度泛函理论方法计算了定域与离域 [Mn3O(O2CH)6L3]z+(L=pyridine; z=0)化合物的电子结构, 得到与实验可比较的磁耦合常数J. 结果表明, 密度泛函理论(DFT)结合对称性破损(BS)方法可用于此三核混合价体系; 对于完全离域的混合价Mn3Ⅱ,Ⅲ,Ⅲ体系, 必须考虑电子的离域作用对磁耦合的影响, 其Hamiltonian量应该包含双交换参数B. 为便于比较, 同时计算了等价三核锰化合物[Mn3O(O2CH)6L3]z+(L=pyridine; z=1)的磁学性质.

关键词: 分子磁性, 混合价, 三核锰, 密度泛函理论, 对称性破损

Abstract: On the basis of classifying mixed-valence compounds, the dimer coupling model was extended to trinuclear magnetic coupling systems. Particular emphasis is placed on the well-localized and well-delocalized mixed-valence compounds. As a representative example, the electronic structure for well-localized and well-delocalized [Mn3O(O2CH)6L3]z+(L=pyridine; z=0) model compounds were calculated via density functional theory, obtained the magnetic coupling constants J compared with experimental data. It is found that the density functional theory combined with broken symmetry approach can be applied to trinuclear mixed-valence systems considered. For well-delocalized mixed-valence Mn3Ⅱ,Ⅲ,Ⅲ system, the delocalization effect of the extra-electron on the magnetic coupling interaction must be considered, and thus the double exchange parameter B should be included in its Hamiltonian. For comparison the magnetic properties of the equivalence trinuclear [Mn3O(O2CH)6L3]z+(L=pyridine; z=1) were also calculated.

Key words: Molecular magnetism, Mixed-valence, Trinuclear manganese, Density functional theory, Broken symmetry

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