The complexation between cyclocarbons and fullerenes was thoroughly studied by Liu and Lu very recently. One of the research topics focused on examining how the interaction between two cyclocarbons and a fullerene changes with the size of the cyclocarbons, IGMH analysis was employed to visually characterize the intermolecular interactions in the trimers, as shown in Fig. . For clarity, the 𝛿𝑔 inter isosurfaces corresponding to the cyclocarbon-fullerene and cyclocarbon-cyclocarbon interactions are colored yellow and green, respectively. From the figure, it can be observed that as the size of the cyclocarbons increases, the area of the yellow isosurfaces gradually increases, directly suggesting that the cyclocarbon-fullerene π-π interaction strengthens. For Cn@C60 with n ranging from 18 to 30, the green isosurface occupies only a small area, indicating that the π-π interaction between the cyclocarbons is present but very weak. In the structure of 2C34@C60, a circular green isosurface with wide coverage appears between the two cyclocarbons, clearly indicating a very strong π-π stacking effect, which also implies that this trimer is highly stable. Indeed, the above speculations based on IGMH analysis are well supported by the interfragment interaction energies calculated using high-precision quantum chemical methods. Additionally, the study found that the area of the 𝛿𝑔 inter isosurface describing the π-π interaction has an ideal linear relationship with the interaction energy between the interacting parts.