Molecular dynamics and kinetic Monte Carlo simulations of protonation dynamics in fuel cell membrane materials and membrane proteins

在这个项目中，我们的目标是解决三个主要目标，这些目标相互关联，并与该项目成功的第一个筹资期的结果直接相关。首先，我们将开发和实施一种尺度桥接方法，用于在延长的时间和长度尺度上模拟质子输运现象。该方法的特殊之处在于，在升级过程中，我们能够从力场甚至基于从头算的分子动力学模拟（MD）中保留最相关的原子结构信息。具体来说，我们将使用来自MD模拟的轨迹数据作为动力学蒙特卡罗方案（kMC）传播矩阵的基础。在应用层面，我们将采用这种组合MD/kMC方案来模拟质子交换膜<s:1> l电池（PEMFC）的新型材料中的质子传导，该材料可承受高温（超过100摄氏度）。通过这种方式，我们将能够跨越我们在这个项目的第一个资助期间遇到的关于长度和时间尺度的限制，这是dü对力场和ab-initio分子动力学技术的固有限制q<e:1>。作为材料科学方向的补充，我们将利用第一个项目阶段QM/MM封顶势的发展，对生物学上非常重要的膜蛋白（infl<s:1> nza M2质子通道）中的质子传输过程进行QM/MM分子动力学模拟。在这种情况下，我们将同样地应用联合的MD/kMC方法来达到更长的时间和长度尺度。综上所述，本项目旨在利用理论化学和化学建模的概念，从材料科学和生化系统两方面理解复杂化学环境下的离子传输现象。

In this project, we aim at addressing three main goals which are interconnected and directly linked to the results of the successful first funding period of this project.First, we will develop and implement a scale bridging method for the simulation of proton transport phenomena on extended time- and length-scales. The special feature of our approach is that we are able to keep the most relevant atomistic structural information from force-field and even ab-initio based molecular dynamics simulations (MD) during the upscaling. Specifically, we will use the trajectory data from the MD simulation as basis for the propagation matrix of a kinetic Monte Carlo scheme (kMC).On the application level, we will employ this combined MD/kMC scheme to simulate proton conduction in novel materials for proton exchange membrane fül cells (PEMFC) which withstand high temperatures (above 100 degree Celsius). In this way, we will be able to cross the restrictions regarding the length- and time-scales that we encountered during the first funding period of this project, which are dü to the inherent limits of the force-field and ab-initio molecular dynamics techniqüs.Complementary to this materials science direction, we will use the developments of QM/MM capping potentials from the first project phase to perform QM/MM molecular dynamics simulations of proton transport processes in a biologically very important membrane protein (the inflünza M2 proton channel). In this context, we will equally apply the combined MD/kMC approach to reach extended time and length scales.In summary, this project aims at creating a joint effort using concepts of theoretical chemistry and chemical modeling, in view of understanding ion transport phenomena from both materials science and biochemical systems in complex chemical environments.