Abstract: The INDO series methods are used to study the two structures of C₆₀CH₂:one is of C_2v geometry with a bridging CH₂ across the bond between two fused six-membered rings in C₆₀;another is C_s geometry with a bridging CH₂ across the bond shared by a five-and a six-membered rings. From the calculated results,including total energy,LUMO-HOMO energy gap,the most stable isomer of C₆₀CH₂ should be tlie C_2v geornetry. Our calculations also find that this C_2v isomer has a cyclopropane-like structure(bridging C₁₅─C₃₀ bond length is 0.1556 nm, the bond-order is equal to 0.8663).The calculated result of electronic spectrum of the C_2v geomety is in good accordance with experimental result.

Key words: C₆₀CH₂(C_2v), C₆₀CH₂(C_s), Electronic spectrum