用三维EHMO晶体轨道程序分别对Ca3C60，Ca5C60进行了能带结构的计算．计算结果表明，Ca3C60没有导电性，能隙约为0．9eV；而在Ca5C60的能带结构中，费米面刚好穿过半满带，表明Ca5C60是导体；同时在费米面附近有较大的态密度值，表明Ca5C60与K3C60等类似，具有较高的超导转变温度．电荷分析表明，在这两种情况下，钙原子的4s电子基本上全转移到C60上，C60分子可形成一个稳定的带6到10个电子的负离子． The band structures of Ca3C60 and Ca5C60 were calculated by three-dimensional EHMO crystal orbital program. The calculated results show that Ca3C60 has no conductivity and the energy gap is about 0.9eV. In the energy band structure of Ca5C60, the Fermi surface passes through the half full band, indicating that Ca5C60 is a conductor. At the same time, a larger density of states Value, indicating that Ca5C60 and K3C60 and similar, with higher superconducting transition temperature. Charge analysis shows that in both cases, the 4s electrons of the calcium atom are substantially fully transferred to the C60 molecule which forms a stable negative ion with 6 to 10 electrons.