计算物理 ›› 2007, Vol. 24 ›› Issue (3): 319-324.

• 论文 • 上一篇    下一篇

(MgB2)n(n=1~3)团簇结构与性质的密度泛函研究

陈玉红1,2, 张材荣2, 康龙1, 罗永春1   

  1. 1. 兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室, 甘肃 兰州 730050;
    2. 兰州理工大学物理系, 甘肃 兰州 730050
  • 收稿日期:2006-02-28 修回日期:2006-07-19 出版日期:2007-05-25 发布日期:2007-05-25
  • 作者简介:陈玉红(1972-),男,甘肃秦安,硕士,副教授,主要从事原子分子理论和团簇物理研究,兰州理工大学理学院730050.
  • 基金资助:
    国家自然科学基金(10547007);甘肃省自然科学基金(3ZS062-B25-022);甘肃省有色金属新材料省部共建国家重点实验室开放基金(SKL05008)资助项目

Structure and Property of (MgB2)n(n=1~3) Clusters:a Density Functional Study

CHEN Yuhong1,2, ZHANG Cairong2, KANG Long1, LUO Yongchun1   

  1. 1. State Key Laboratory of Gansu Advanced Non-ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050, China;
    2. Department of Physics, Lanzhou University of Technology, Lanzhou 730050, China
  • Received:2006-02-28 Revised:2006-07-19 Online:2007-05-25 Published:2007-05-25

摘要: 用密度泛函理论(DFT)的杂化密度泛函B3LYP目的在6-31G*基组水平上对(MgB2)n(n=1~3)团簇各种可能的构型进行几何结构优化,预测各团簇的最稳定结构,并对其振动特性、成键特性、极化率和超极化率等性质进行理论研究.结果表明,团簇的几何结构大多是平面结构,团簇的稳定结构中通常是几个呈负电性的B原子形成一个负电中心,而其他B原子和Mg原子处在端位,且显正电性,Mg原子的自然电荷在+0.559e~+0.920e之间,B原子的自然电荷在-0.724e~+0.197e之间;团簇中通常是B-B键和B-Mg键共存,较少出现Mg-Mg键,计算得到的B-B键键长在0.153~0.182 nm之间,B-Mg键键长在0.218~0.231 nm之间.

关键词: (MgB2)n(n=1~3)团簇, 密度泛函理论, 结构与性质

Abstract: Possible geometrical structures and relative stability of (MgB2)n(n=1~3) clusters are studied with a hybrid density functional theory(B3LYP) with 6-31G* basis sets.For the stablest isomers of (MgB2)n(n=1~3) clusters,the electronic structure,vibrational property,bond,ionization potential,polarizability and hyperpolarizability are analyzed. Most of the optimized (MgB2)n(n=1~3) clusters are planar structures and the B-B and B-Mg bonds coexist,while the Mg-Mg bonds are infrequent.The bond lengths of B-B and Mg-B are 0.153~0.182 nm and 0.218~0.231 nm,respectively. Several negative B atoms form an electronegative center and other B and Mg atoms with positive charge are located at the apex of the cluster.The natural charges of Mg atom and B atom are +0.559e~+0.920e and -0.724e~+0.197e,respectively.

Key words: (MgB2)n(n=1~3) clusters, density functional theory, structure and properties

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