. It shows the coherence persists less than 200 fs. Based on our model, we conclude that this frequency is close to th energy gap between the electronic singlet states in pentacene dimer and it should strongly relate to the evidence of electronic coherence. Thus, what we observe here is the interplay of electronic coupling of two pentacene molecules and the vibornic interactions to the vibrational modes, which results in a complicated structure of PESs between singlet and triplet-pair states forming conical intersection. This makes the coherent dynamics extremely intricated and also generates the new coherent frequencies during the SF process.