Fig. 3
From: Coherent exciton-vibrational dynamics and energy transfer in conjugated organics
Electronic and vibrational dynamics of four model systems. a–d Correspond to the Oligomer, Nanohoop, Dendrimer, and Dimer, respectively, as presented in Fig. 2. In order to synchronize the NA transitions among individual trajectories, we introduce the convenient time variable Δt = t − thop. The exact moment of NA transition, which varies among trajectories, is set to Δt = 0. Negative values of Δt correspond to times before the NA transition and positive values represent times after the transition. a The evolution of the average bond-length alternation, BLA, for the right (black) and left (red) molecular halves of the linear oligomer reveals out-of-phase oscillations corresponding to the change in localization between the two sides of the molecule confirmed by orbital plots of the transition density for snapshots taken during dynamics. b The evolution of the average benzene–benzene dihedral angle for the top (red) and bottom (black) molecular halves of the nanohoop indicate displacements of the ground state vibrational normal modes recovered after 200 fs. The corresponding orbital plots of the transition density for snapshots during dynamics reveal a transfer of wavefunction from bottom to top half of the nanohoop. c The evolution of the fraction of the transition density on the left branch of the dendrimer is plotted for a typical single trajectory (blue) and the ensemble average (red). The time axis denotes the time from the S3 to S2 transition (hop). Before the transition (t − thop < 0), the system on the upper state experiences oscillations between the two branches. After the transition to the lower state (t − thop > 0), the exciton becomes trapped in a single branch. The change in wavefunction localization is confirmed by orbital plots of the transition density during dynamics revealing transfer between left and right branches. d The evolution of the fraction of the transition density on the top monomer of the dendrimer is plotted for a typical single trajectory (blue) and the ensemble average (red). The oscillations correspond to the transfer between the top and bottom monomer shown in the orbital plots of the transition density taken from snapshots during dynamics
