Acta Phys. -Chim. Sin. ›› 1995, Vol. 11 ›› Issue (02): 131-134.doi: 10.3866/PKU.WHXB19950207

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Band Structure Studies for Crystalline Ca3C60 and Ca5C60

Cao Yang, Chen Liang-Jin, Chen Bo, Feng Jian-Wen   

  1. Department of Chemistry,Suzhou University,Suzhou 215006
  • Received:1994-01-03 Revised:1994-03-15 Published:1995-02-15
  • Contact: Cao Yang

Abstract:

 Three dimensional EHMO crystal orbital calculations for crystalline Ca3C60 and Ca5C60 are reported. The ground state of partially doped Ca3C60 is found to be insulating with an indirect energy gap of 0.5eV. In contrast, Ca5C60 forms a metallic conducting phase with a set of three half-filled bands crossing the Fermi level which is found to be located close to the peak of the density of state. The character of crystal orbitals near the Fermi-level for both Ca3C60 and Ca5C60 is completely carbon-like. In both cases, the Ca atoms are almost fully ionized and C60 molecules can form a stable negative charge state with six to ten additional electrons. The projected DOS of Ca atoms near the Fermi-level and the overlap populations between Ca and C are neglectible.

Key words: Doped C60, Band sructure, EHMO