Dear all, As is shown in the title, I tried to combine SF-TDDFT with FSSH to investigate S1->S0 process. For example, I tried this for ethylene. Firstly, I performed a single point SF-TDDFT job to find singlet states. Below text is copied from output. Excited state 1: excitation energy (eV) = -4.1688 Total energy for state 1: -78.52970653 au <S…