Interaction of electronic structure and nuclear dynamics on the S-1 reaction surface for the ring opening of cyclohexadiene

For the ultrafast photoinduced ring opening of cyclohexadiene the S-1 state plays a central role, providing the possibility to rapidly decay to the ground state. In this paper we follow the path of a wavepacket propagating in the reactive coordinate space of the S-1 surface. We present a detailed analysis of the corresponding electronic and nuclear motions. With the help of a projection method and a normal-mode analysis, the vibrational modes driving the reaction might be detected experimentally.