Frequencies and normal mode displacements were calculated at the ground-state minimum energy position and used in the Wigner sampling. To enhance convergence and stability of the excited-state electronic structure calculations during the dynamics simulations, an additional ghost-state (S 3 ) was included, which was not considered in the propagation. As underlying electronic structure method, time-dependent density-functional-theory was applied using the B3LYP functional 65 and Pople's 6-31G* basis set, as implemented in the Q-Chem program package. Following the same protocol as for the model systems, first 100 trajectories were propagated for 100 fs with a 0.5 fs timestep based solely on ab-initio calculations and starting from the S 2 state. The data was stored in the database and subsequently the nearby points were deleted. The threshold for regions with small energy gaps (< 0.5 eV) was 0.05 Bohr, whereas for areas where the surfaces are well separated the radius is 0.1 Bohr (using the euclidean norm). By this, a database with 1524 datasets was generated. Moreover, a grid in internal coordinates, containing 1759 datapoints, was added to the training data, to make sure that no extrapolation is needed. The datapoints are shown in Fig. for both simulations about 85% of the population is in the S 1 state. At about 50 fs, a small population transfer is observed to the ground state (black) for both methods. However, the energy-only simulations predict a larger transfer, which leads to a final occupation of the ground state of more than 5%. The results are also in good agreement with surface hopping simulations using the linear vibronic coupling scheme 4 (see SI). Comparing computational times shows the speedup by the interpolation compared to direct ab-initio calculations.