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、模型和计算方法项目的一个奖项的支持，以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运输。这些模拟包括构成分子中原子的电子和原子核的量子力学性质。 Markland的方法允许在模拟过程中建立和破坏化学键，这对于理解质子等轻原子的运输和化学反应性至关重要。无序系统中的质子传输过程在从化学和材料科学到地质学和生物学等系统中具有根本重要性。这些包括在燃料电池和生物质子通道中使用的质子交换膜中的运输机制的阐明，提供对其功能的见解，以及如何调整这些材料以实现高效质子运输。Markland教授还在开发模拟和可视化体验，以改善高中教育，并鼓励更多的学生通过在他的实验室里接待高中教师来学习化学。这些模拟和可视化的经验帮助教师实施科学练习，吸引学生的兴趣，并激发他们对自然世界的探究。这是通过与几个斯坦福大学外联方案合作实现的。这项研究的目的是了解质子缺陷在异质环境中的结构和动力学，与发展的方法，以加速从头算路径积分分子动力学模拟。这些方法利用时间和长度尺度的分离方法，以提高这些模拟的效率的基础上环聚合物收缩和多个时间尺度的分子动力学算法。 Markland和他的研究小组使用这些方法来研究结构和动力学在包含质子缺陷的各种异质系统中的相互作用，从疏水和亲水界面到纳米多孔系统。这些研究正被用来了解如何调整化学环境来改变质子缺陷的运输和反应性

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