Possible stable structures of C~3~6 dimers ((C~3~6)~2) are investigated using B3LYP hybrid Hartree-Foch/density-functional- theory method at 3-21G level. The most energetically favorable structure is predicted to be the D~2~h isomer of which the two C~3~6 are joined by twoC－C bonds through face to face of hexagon planes. the calculated results lead to the bond length of 0.151～0.169nm between the two C~3~6 cages for all the (C~3~6)~2 studied here, which indicates that the two C~3~6 are bounded covalently. The stability and the lengths of bonds linking the two C~3~6 cages for the (C~3~6) ~2 are highly correlated to the binding position. The electronic structures and their influences on the properties of (C~3~6)~2 are also discussed.

Key words: DIMER, STABILITY, ELECTRONIC STRUCTURE