The dynamics are then investigated with full-dimensional Trajectory Surface Hopping (TSH) simulations (Richter2011, Mai2018) carried out on potential energy surfaces obtained by application of the linear vibronic coupling (LVC) model based on the harmonic oscillator approximation (Koppel1984, Zobel2021) (S.I.2). In order to keep the calculations tractable for the high-energy excitation that involves a dense manifold of coupled electronic states, some approximations are introduced. First, the size of the system is reduced from NiTMP to Nickel(II) tetramethylporphyrin (NiTMeP) (Figure ). Second, the simulations are performed in vacuum in order to prevent introducing any effect from the surrounding solvent treated here as a continuum.