Upon calculating the bond lengths and dihedrals, specifically the C 5 -C 6 bond distance, significant differences are observed between clusters 0 and 1 (Figure ). The mean values of these distributions are noticeably different. Cluster 2 shows more dispersed values, particularly in the green distribution, which likely corresponds to the 90° rotation discussed earlier. The blue cluster primarily consists of geometries with shorter bond lengths. In contrast, the yellow cluster includes geometries with an extended C 5 -C 6 bond length. The markers in this plot correspond to the hopping geometries. It becomes evident from this analysis that some hopping geometries belong to cluster 1 (yellow). In contrast, a few others, represented by smaller markers, belong to cluster 2. By analyzing the geometries within cluster 2, it has been confirmed that they correspond to the 90-degree rotated structures. These kind of structures are responsible for less than 5% of the decay population of fulvene. Meanwhile, the hopping geometries in cluster 1 are associated with an elongated C 5 -C 6 bond length, and the geometries in cluster 0 exhibit various other distortions.