The difference between the adiabatic and diabatic S 0 populations can be understood by investigating the behavior of trajectories undergoing deactivation within the singlet manifold in more detail. To do this, we show the the potentials of the singlet (blue lines) and triplet (red lines) electronic states along an example trajectories in Figure , where the active electronic is marked by black circles. Figure (a) shows the ultrafast relaxation of a trajectory within the singlet manifold from the initial excited singlet state to the adiabatic ground state within 22 fs. Analyzing the diabatic character of this state reveals predominant MLCT and 1 MC characters. This state is still close in energy to the excited singlet and triple states, indicating, that it is still displaced from the Franck-Condon geometry (where adiabatic and diabatic S 0 states coincide). Thus, this state is denoted as S * 0 and can be viewed as a hot ground state. The S * 0 is maintained in the trajectory until ca. 635 fs, where the dominant character changes to the diabatic S 0 and the state separates in energy from the excited singlet and triplet states, see Figure . The full simulation of 0-1000 fs of this trajectory is also shown in Figure