北京大学学报(自然科学版)

Eu2S, EuS2电子结构和化学键的密度泛函理论研究

刘文剑, 林宪杰, 黎乐民   

  1. 北京大学化学与分子工程学院,稀土材料化学及应用国家重点实验室,北京,100871
  • 收稿日期:1997-04-02 出版日期:1998-07-20 发布日期:1998-07-20

Study on the Electronic Structure and Chemical Bonding of Eu2S and EuS2 by Means of Density Functional Theory

LIU Wenjian, LIN Xianjie, LI Lemin   

  1. College of Chemistry and Molecular Engineering, State Key Laboratory of Rare Earth Materials Chemistry and Applications, Peking University, Beijing, 100871
  • Received:1997-04-02 Online:1998-07-20 Published:1998-07-20

摘要: 利用密度泛函理论方法(DFT)对Eu2S, EuS2的电子结构和化学键进行了研究。结果表明:Eu2S和EuS2分子中的Eu-S键均主要来自Eu 5d和S 3p轨道的相互作用,4f轨道基本上是定域的,Eu原子轨道对Eu-S键的贡献大小顺序均为5d>6p>6s>4f。电子结构特征表明,在Eu2S和EuS2中,Eu均保持为2价,4f轨道不能成为成键轨道的主要成分;Eu-S键的共价性成分分别为68%和57%。

关键词: Eu2S, EuS2, 密度泛函理论, 电子结构, 化学键

Abstract: The electronic structure and chemical bonding of Eu2S and EuS2 have been studied by means of the density functional theory. It is shown that the Eu-S bonding mainly comes from the interaction between Eu 5d and S 3p orbitals in both molecules. The 4f orbitals are localized in essence. The contribution of the Eu atomic orbitals to the Eu-S bonding follows the order: 5d>6p>6s>4f. The characteristics of the electronic structure show that the valence of Eu is 2 both in Eu2S and EuS2, which shows that the 4f orbitals can not become the signifacant component of the bonding molecular orbitals. The covalency of the Eu-S bond is 68% in Eu2S and 57% in EuS2.

Key words: Eu2S, EuS2, density functional theory, electronic structure, chemical bonding

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