Efficient algorithms for the simulation of the non-adiabatic exciton transfer dynamics in light-harvesting systems

通过捕光复合物捕获太阳光是生物系统中光合作用的第一步。为了了解光合系统的捕光复合物的结构和功能之间的微妙关系，实验数据必须通过计算机模拟来增强，这使得能够阐明这些复合物用于有效能量转换的过程的结构-功能关系和机械方面的更详细的图片。在过去的几年里，主要的理论进展开辟了途径的方法来计算激子转移过程中一个更直接的方式。这涉及到快速和足够准确的半经验方法来描述基态和激发态特性的发展，结合到多尺度方法来解决巨大的系统，包括其复杂的动力学效应。在这个提议中，我们希望将联合收割机平衡良好的半经验量子化学与力场方法和电子自由度的非绝热传播方法相结合，这将允许直接遵循激子动力学。基于这种组合，将计算实验观测值进行比较和论证。我们要解决几个不同的系统，LH 2，LH 3，FMO和PC612复合物。到目前为止，这些系统已经在实验上得到了很好的研究，因此它们是理想的基准测试新方法，并显示模拟如何增加洞察力，这是迄今为止无法通过实验获得的。主要目标是开发一种可靠但有效的方法，可应用于其他生物和新的人工捕光复合物。

The capture of sunlight by light-harvesting complexes is the first step of photosynthesis in biological systems. In order to understand the subtle relationship between structure and function in light-harvesting complexes of photosynthetic systems, experimental data have to be augmented by computer simulations, which allow to elucidate a more detailed picture of the structure-function relationship and the mechanistic aspects of the processes used by these complexes for an efficient energy conversion. In the last years, major theoretical advances open the pathway for approaches to compute exciton transfer processes in a much more direct way. This concerns the development of fast and sufficiently accurate semi-empirical methods to describe the ground and excited states properties, combined into multi-scale approaches to address huge systems including their complex dynamical effects. In this proposal, we want to combine well balanced semi-empirical quantum chemistry with force field methods and non-adiabatic propagation approaches for the electronic degrees of freedom, which will allow to follow the exciton dynamics directly. Based on this combination, experimental observables will be computed for comparison and justification. We want to address several different systems, the LH2, LH3, FMO and PC612 complexes. Theses systems have been well studied experimentally so far, therefore they are ideal to benchmark out new approach and show, how simulation can add insights, which so far could not be gained experimentally. The major goal is to develop an reliable but yet efficient methodology, which can be applied to other biological and new artificial light-harvesting complexes.