Due to the flexibility of cyclocarbons, their complexation with C60 fullerene may lead to deformation in different degrees. To quantify this effect, we calculated the deformation energy (Edef) of the cyclocarbons in different C60@Cn dimers, and the data are given in Table . It can be seen that the Edef is almost zero from C18 to C34, showing that the deformation of ring structures during complexation is negligible.