Ab initio description of the quantum mechanics in light-harvesting complexes of purple bacteria

紫色细菌光捕获复合物中量子力学的从头计算

• 批准号: 18592143
• 负责人: Professor Dr. Ulrich Kleinekathöfer
• 金额: --
• 依托单位: Department of Physics and Earth Sciences
• 依托单位国家: 德国
• 项目类别: Research Grants
• 财政年份: 2005
• 资助国家: 德国
• 起止时间: 2004-12-31 至 2010-12-31
• 项目状态: 已结题
• 来源: https://gepris.dfg.de/gepris/projekt/18592143?language=en
• 关键词: Ab; initio; description; quantum; mechanics

The complex and subtle relationship between structure and function, i.e. light-harvesting, of photosynthetic systems has been studied conjointly with high-resolution crystallographic structures, ultrafast spectroscopy and quantum chemical calculations. The aim of the proposal is to start at the available crystal structure of the light-harvesting system 2 (LH2) of purple bacterium Rhodopseudomonas acidophila, perform a molecular dynamics simulation and then use the obtained thermal fluctuations of the nuclear positions as input for quantum chemical calculations. Based on the results of these quantum chemical calculations a refined quantum mechanical model shall be applied to the determination of optical spectra. This way one can construct a model with unprecedented accuracy and without fitting parameters. Besides static and transient spectra of ensembles of LH2 rings, another focus shall be on the theoretical determination and classification of single-molecule spectra. The model also allows for the incorporation of the carotenoids into the model and to treat them on the same footing as the bacteriochlorophylls which constitute the ring systems. Modeling of recent coherent control experiments on the energy transfer between carotenoids and the rings in the LH2 is a further goal of the project.

结合高分辨晶体结构、超快光谱和量子化学计算，研究了光合作用系统结构和功能之间的复杂而微妙的关系。该方案的目的是从紫色细菌嗜酸红假单胞菌的捕光系统2(LH2)的可用晶体结构入手，进行分子动力学模拟，然后使用获得的核位置的热涨落作为量子化学计算的输入。根据这些量子化学计算的结果，应采用改进的量子力学模型来确定光谱。这样，人们就可以在不需要拟合参数的情况下，以前所未有的精度构建模型。除了LH2环系综的静态和瞬变光谱外，另一个重点应放在单分子光谱的理论确定和分类上。该模型还允许将类胡萝卜素合并到模型中，并与构成环系的细菌-叶绿素一样对待它们。对最近关于类胡萝卜素和LH2中环之间的能量转移的相干控制实验进行建模是该项目的另一个目标。