【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Ｅｕ５ｄ和Ｓ３ｐ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％。更多还原

【Abstract】 The electronic structure and chemical bonding of Eu 2S and EuS 2 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 5d 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 Eu 2S and EuS 2,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 Eu 2S and 57% in EuS 2.更多还原