In these inequalities, 1L E  and 1L f are the excitation energy and oscillator strengths between the ground (1) and L states. r is a random number sampled from a uniform distribution in the [0,1] interval. f max is the maximum oscillator strength value among all sampled geometries and states. The first inequality ensures that the initial state is in the excitation window of interest. The second inequality selects preferentially states with large transition probabilities (proportional to the oscillator strength ). This algorithm leads to an ensemble of trajectories starting in several adiabatic states (Figure ).