物理化学学报 >> 1998, Vol. 14 >> Issue (05): 413-418.doi: 10.3866/PKU.WHXB19980506

研究论文 上一篇    下一篇

表观价态异常分子EuS2和Eu2S的泛函理论研究

吕海港, 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:1997-08-29 修回日期:1997-12-03 发布日期:1998-05-15
  • 通讯作者: 黎乐民

Study on the Molecules EuS2 and Eu2S with Apparently Abnormal Valence by Means of Density Functional Theory

Lv Hai-Gang, Li Le-Min   

  1. College of Chemistry and Molecular Engineering,State Key Laboratory of Rare Earth Materials Chemistry and Applications,Peking University,Beijing 100871
  • Received:1997-08-29 Revised:1997-12-03 Published:1998-05-15
  • Contact: Li Le-Min

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摘要：

用密度泛函理论方法研究了EuS2和Eu2S的分子结构、电子结构和成键情况．结果表明EuS2有弯曲构型和直线构型，而Eu2S只有弯曲构型．在S－S和Eu－Eu之间的在化学键．在这两个分子中，Eu和S的价层满足8电子规律，保持其正常价态．第一电离势和原子化能的计算值与实验结果符合较好．相对论效应对分子几何构型和振动基频影响较小，对分子轨道能级顺序和键能有较显著的影响，但旋轨偶合起的作用不大.

关键词: EuS2, Eu2S, 分子结构, 电子结构, 密度泛函理论

Abstract:

The density functional theory is used to study the molecular structure, electronic structure and chemical bonding of EuS2 and Eu2S. It is shown that EuS2 has both bent and linear configurations, whereas Eu2S has only the bent one. There is chemical bond between S-S, as well as between Eu-Eu atoms. In these molecules, Eu and S are in the normal valent state with their valence shell satisfying the octet rule. The calculated ionization potentials and atomization energies are in fairly good agreement with the experimental values. The relativistic effects only slightly influence the geometry and vibrational frequency of the molecules while significantly influence the MO levels and the bonding energy, but the spin-orbit interaction does not result in an important effect.

Key words: EuS2, Eu2S, Molecular structure, Electronic structure, Density functional theory