bond stretching character, are displayed in Figure . The simulation produces relaxation trajectories on the potential energy hypersurface that involves all possible modes, and the presented results are obtained as average trajectories and populations from the numerous time-dependent runs. The excitation process occurs from 1 GS predominantly to the lowest-lying optically bright 1 MLCT states with a minor 1 MC component, as extracted from the simulated electronic populations at t = 0 fs. In Figure , we present the time-dependent excited-state populations as obtained by the full-dimensional dynamics simulations (solid lines). From this figure, we observe a very fast (∼50 fs) MLCT → 3 MLCT ISC, consistent with known photophysics of TM complexes with singlet GS. Afterwards, the 3 MC, and subsequently, the 5 MC states are populated, to which latter state the conversion is nearly complete in ∼500 fs. Importantly, the simulated dynamics shown in Figure are in very good overall agreement with the results of the most extensive TR-XES study on [Fe(bipy) 3 ] 2+ (ref. 9), which substantiates the accuracy of our results.