Institute of Chemical Physics, Vilnius University, Sauletekio al. 9-III, Vilnius 10222, Lithuania.
J Chem Phys. 2021 Jun 7;154(21):214115. doi: 10.1063/5.0048815.
Exciton energy relaxation in a bacterial Reaction Center (bRC) pigment-protein aggregate presumably involves emission of high energy vibrational quanta to cover wide energy gaps between excitons. Here, we assess this hypothesis utilizing vibronic two-particle theory in modeling of the excitation relaxation process in bRC. Specific high frequency molecular vibrational modes are included explicitly one at a time in order to check which high frequency vibrations are involved in the excitation relaxation process. The low frequency bath modes are treated perturbatively within Redfield relaxation theory. The analysis of the population relaxation rate data indicates energy flow pathways in bRC and suggests that specific vibrations may be responsible for the excitation relaxation process.
在细菌反应中心（bRC）的色素 - 蛋白聚集体中，激子能量弛豫可能涉及发射高能振动量子来覆盖激子之间的宽能隙。在这里，我们利用双粒子理论中的振子理论来评估这一假设，以模拟 bRC 中的激发弛豫过程。具体的高频分子振动模式被逐个明确地包含在内，以检查哪些高频振动参与了激发弛豫过程。低频浴模式在 Redfield 弛豫理论中被微扰处理。对种群弛豫率数据的分析表明了 bRC 中的能量流途径，并表明特定的振动可能是激发弛豫过程的原因。
