Tools for Accurate Photoelectrochemistry in Complex Environments

麻省理工学院的特洛伊·范·沃里斯得到了化学部化学理论、模型和计算方法计划颁发的奖项的支持，该计划开发理论方法和工具，以揭示如何利用可再生能源，如太阳能和来自可持续能源的电力，更好地完成复杂的化学转化。这种系统的微观结构非常复杂，这些装置中结构-功能关系的性质还没有被很好地理解。模拟和建模在揭示可用于优化设备性能或为特定应用提出全新体系结构的设计原则方面发挥着至关重要的作用。在这项研究过程中开发的技术将适用于在许多重要技术应用中发挥关键功能的分子，如人工光合作用、有机发光二极管、催化和化学传感。在更广泛的影响方面，调查人员积极参与扩大可通过edX平台提供的与化学有关的问题类型的基础。根据这一奖项，范·沃赫斯研究小组计划开发和实施专注于将基态电子结构理论的技术扩展到精确处理电子激发态的计算工具。为了改善对电子激发态的描述，研究人员将设计电子嵌入方案，即使是高度离域的系统，也能为局部电子结构提供可控的精度。这些方法将与一套非局部密度函数工具相辅相成，以包括筛查等远程相互作用。在这项电子结构工作的同时，该团队试图开发能够从短时间从头计算模拟中提取长时间动力学数据的分子动力学技术。这些技术旨在理解两个关键的电子过程：共轭聚合物中的载流子离域和无机半导体的带隙。除了这些案例研究，这项工作还旨在创建一套通用技术，用于准确描述溶液中的光化学和表面的电化学。

Troy Van Voorhis of the Massachusetts Institute of Technology is supported by an award from the Chemical Theory, Models and Computational Methods program in the Chemistry division to develop theoretical methods and tools to reveal how complex chemical transformations can better be accomplished using renewable energy sources such as sunlight and electricity derived from sustainable sources. The microscopic structure of such systems is very complex and the nature of structure-function relationships in these devices is as yet not well understood. Simulation and modeling play a crucial role in uncovering design principles that can be exploited to optimize device performance or to propose entirely new architectures for specific applications. The techniques developed in the course of this research will be applicable to molecules that play key functional roles in many important technological applications such as artificial photosynthesis, organic LEDs, catalysis and chemical sensing. In terms of broader impact, the investigators are actively involved in expanding the base of chemistry-related problem types that can be offered through the edX platform. Under this award, the Van Voorhis research group plans to develop and implement computational tools that that focus on extending the techniques of ground state electronic structure theory to the accurate treatment of electronic excited states. In order to improve the description of electronic excited states, the investigators will design electronic embedding schemes that offer controllable accuracy for the local electronic structure even of highly delocalized systems. These methods are to be complemented with a set of nonlocal density functional tools for including long-ranged interactions such as screening. Contemporary with this electronic structure work, the team seeks to develop molecular dynamics techniques capable of extracting long time kinetic data from short time ab initio simulations. These techniques are designed to understand two key electronic processes: charge carrier delocalization in conjugated polymers and the band gaps of inorganic semiconductors. Beyond these case studies, the work also aims to create a palette of general techniques for the accurate description of photochemistry in solution and electrochemistry at surfaces.