CAREER: Investigating the structure and dynamics of proton defects in heterogeneous environments with accelerated quantum simulations

斯坦福大学的托马斯·马克兰得到了化学理论、模型和计算方法计划的支持，该计划旨在开发加速分子模拟的技术。特别关注的是质子在复杂环境中的传输。这些模拟包括组成分子中原子的电子和原子核的量子力学性质。Markland的方法允许随着模拟的进行而建立和断开化学键，这对于了解质子等轻原子的输运和化学反应是必不可少的。无序体系中的质子输运过程在从化学和材料科学到地质和生物学的各种系统中都具有重要的意义。这些内容包括阐明燃料电池和生物质子通道中使用的质子交换膜的传输机制，提供对其功能的见解，以及如何调整这些材料以实现高效的质子传输。马克兰教授还在开发模拟和可视化体验，以改善高中教育，并通过在他的实验室接待高中教师来鼓励更多的学生学习化学。这些模拟和可视化的体验有助于教师实施科学练习，激发学生的兴趣，激发他们对自然世界的探究。这是通过与斯坦福大学的几个外展项目合作实现的。这项研究旨在了解非均相环境中质子缺陷的结构和动力学，同时开发加速从头算路径积分分子动力学模拟的方法。这些方法利用时间和长度尺度的分离方法来提高这些基于环聚合物收缩和多时间尺度分子动力学算法的模拟的效率。马克兰和他的研究小组使用这些方法来研究从疏水和亲水界面到纳米孔系统的各种含有质子缺陷的非均相系统中结构和动力学的相互作用。这些研究被用来理解如何调整化学环境来改变质子缺陷的传输和反应能力。

Thomas Markland of Stanford University is supported by an award from the Chemical Theory, Models and Computational Methods program to develop techniques to speed up molecular simulations. The particular focus is on transport of protons in complex environments. These simulations include the quantum mechanical nature of the electrons and nuclei that make up the atoms in a molecule. Markland's approach allows for making and breaking chemical bonds as the simulation progresses, which is essential for understanding the transport and chemical reactivity of light atoms such as protons. Proton transport processes in disordered systems are of fundamental importance in systems ranging from chemistry and materials science to geology and biology. These include the elucidation of transport mechanisms in proton exchange membranes used in fuel cells and in biological proton channels, providing insights into their functionality, and how to tune these materials for high efficiency proton transport. Professor Markland is also developing simulation and visualization experiences to improve high school education as well as to encourage more students to study chemistry by hosting high school teachers in his lab. These simulation and visualization experiences aid teachers in implementing scientific exercises that engage students' interest and stimulate them to inquire about the natural world. This is being achieved via partnership with several Stanford outreach programs. This research is aimed at understanding of the structure and dynamics of proton defects in heterogeneous environments, in concert with the development of approaches to accelerate ab initio path integral molecular dynamics simulations. These methods exploit time- and length-scale separation approaches to increase the efficiency of these simulations based on ring polymer contraction and multiple time-scale molecular dynamics algorithms. Markland and his research group use these approaches to investigate the interplay of structure and dynamics in a wide range of heterogeneous systems containing proton defects ranging from hydrophobic and hydrophilic interfaces to nanoporous systems. These studies are being used to understand how the chemical environment can be tailored to change the transport and reactivity of proton defects