Remarkably, internal conversion to the ground state is slower for Ada-CN + than for Ama + , ∼120 fs vs. ∼25 fs, despite a smaller initial excitation energy (see Tab. 2). Specifically, the mean excitation energy calculated at the initial geometries is 2.57 eV for Ama + and 2.36 eV for Ada-CN + . Thus, the observed situation violates the well-known energy-gap law which predicts a faster rate for internal conversion due to nonadiabatic couplings with a decreasing energy gap between states . Moreover, when comparing all three cations, we see that Ama + exhibits the fastest excitedstate decay, while possessing the largest initial excitation energy at the same time. However, the energy-gap-law argument qualitatively holds when comparing Ada + to Ada-CN + (Tab. 2). ), and (c) Ada-CN + . For Ama + and Ada-CN + , the excitation energy window of eV is used. And Ada + is excited to the D 3 /D 4 states . To analyze the departure from the energy-gap law observed when comparing Ama + with Ada-CN + , we calculated energy gaps and nonadiabatic coupling terms (scalar products d ij • Ṙ with d ij being the nonadiabatic, first-derivative coupling vector between states i and j, and Ṙ nuclear velocities) between selected states. Specifically, in Fig. , we plot the D 3 population for Ada-CN + and the D 1 and D 2 populations for Ama + , i.e., for those states which are initially populated the most when selecting the eV excitation window (cf. Tab. 2). The corresponding energy gaps expected to be most relavant for the relaxation to the ground state D 0 are the D 0 -D 1 energy gaps for both cations as well as the D 1 -D 2 energy gap for Ama + and the D 2 -D 3 energy gap for Ada-CN + (Fig. ). For two of these pairs we also show the nonadiabatic coupling terms, i.e., those between states D 1 and D 2 for Ama + and between states D 2 and D 3 for Ada-CN + (Fig. ). The shown curves are averages over the swarm of trajectories. In the case of the nonadiabatic coupling, the absolute values were averaged.