No further fragments were found in our simulations with exception of one trajec-tory for Ama + , which demonstrated an NH 2 loss. We note that other fragmentation channels were observed in the experiment for Ada-CN + (notably HCN loss) , which presumably require a (much) longer time to be realized. Further, in addition to the H loss dissociation reaction, we have also observed intramolecular bond-breaking and rearrangement of the carbon cage. To do so, we compared initial bond lengths with the final distances (for the same pairs of atoms) and counted a reactive event if the final distance was more than 1.5 times larger than the initial one. The percentage of the trajectories showing rearrangement, calculated as 100 % × N rearr /(N tot -N H-loss ) (here, N rearr is the number of trajectories showing intramolecular bond breaking, N tot is the number of all trajectories, and N H-loss is the number of trajectories showing H loss), is presented in Fig. , for the three sets of the SH simulations. Remarkably, in the case of Ama + , ∼87 % of parent ion trajectories undergo rearrangement. Examples of the rearranged structures are shown in Fig. . The high rearrangement percentage is in agreement with the recent reports by George and Dopfer , who observed Ama + cage-opening by means of infrared photodissociation spectroscopy and also calculated a lower barrier for this reaction in the case of Ama + in comparison with Ada + . For Ada + , the rearrangement percentage is ≲2 % for excitation energies ≲3 eV (and ≲7 % when considering higher excitation energies). [We note that these values are slightly larger than those reported in ref. because there we used the factor of 2 instead of 1.5 (used here, see above) to judge on the rearrangement event.] In the case of Ada-CN + , much less trajectories demonstrated rearrangement in comparison to Ama + , 2.5 % for the energy window of eV and 6.3 % for eV. Thus, Ada-CN + behaves more similar to Ada + in this respect. with B3LYP predicting Ama + ≈ Ada + > Ada-CN + , CAM-B3LYP Ama + > Ada + > Ada-CN + , and ROOM3/CISD Ama + > Ada + ≈ Ada-CN + . In addition, the vibronic spectra show differences between the cations-no fine structure was found for Ama + in contrast to Ada + and Ada-CN + .