Coherent nuclear and electronic dynamics in primary charge separation in photosynthetic reaction centers: A redfield theory approach

Primary charge separation dynamics is modeled in the pheophytin-modified Rhodobacter sphaeroides R-26 reaction center (RC). To explain the observed spectral evolution, it is assumed that the process is coupled to coherent nuclear motion. A density matrix equation with the Redfield relaxation superoperator is used for simulation of the electron-vibratibnal dynamics and its spectral signatures. The model includes two diabatic - states, i.e., an excited state P* of the primary donor (i.e., special pair, P), and a charge-transfer state (