Acta Phys. -Chim. Sin. ›› 1998, Vol. 14 ›› Issue (05): 413-418.doi: 10.3866/PKU.WHXB19980506

• ARTICLE • Previous Articles     Next Articles

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


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