CAREER: Self-consistent models of electronic dynamics and relaxation

圣母大学的约翰·帕克希尔获得了化学理论、模型和计算方法计划以及化学部高分子、超分子和纳米化学计划的支持，以开发理论和计算机软件来模拟光刺激分子中的电子运动。该软件允许用户预测材料的重要光动力学性能。例如，它可以用于改进光伏材料、颜料、光学介质、有机发光二极管和其他发光/吸收材料，而不需要昂贵的合成试验和错误。关于光如何使电子云运动，以及这些电子如何因原子核和其他周围材料的振动而损失能量的改进的数学模型，是这些发展的基础。约翰·帕克希尔和他的研究小组还开发了一个开源的化学门户网站，化学社区和教育工作者可以在这里访问和应用这些工具，而不需要昂贵的计算机硬件、软件或专业知识。ParkHill小组追求自洽的方法来研究非平衡量子电子动力学，使用动态嵌入提供了一个处理扩展系统、关联和振动效应的公共框架。这些工具流畅地将分子量子力学的标准工具箱扩展到电子态在统计上混合的区域。发展了一种自洽的超越平均场关联动力学方法来研究电子关联和退相干之间的相互作用。帕克希尔小组的S实时瞬变吸收技术被推广到重现相干多维实验。这些新工具被用来产生光致电荷分离的实时模拟，其特点是精确处理量子关联效应、热化和分子的环境环境。这些模拟揭示了光伏技术中控制等离子体产生超热电子和电荷分离的机制。嵌入式动力学方法论是对现有方法的补充，为研究凝聚系统中的电子动力学提供了一个统一的、系统可改进的平台。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

John Parkhill of The University of Notre Dame is supported by an award from the Chemical Theory, Models and Computational Methods program and the Macromolecular, Supramolecular and Nanochemistry program in the Chemistry Division to develop theories and computer software to model the motion of electrons in molecules that are stimulated by light. This software allows users to predict important photodynamic properties of materials. For example it could be used to improve photovoltaic materials, pigments, optical media, organic light emitting diodes, and other light emitting/absorbing materials without expensive synthetic trial-and-error. Improved mathematical models for how light imparts motion on clouds of electrons, and how these electrons lose their energy to vibrations of atomic nuclei and other surrounding material underlie these developments. John Parkhill and his research group also develop an open source chemistry web portal where the chemical community and educators can access and apply these tools without expensive computer hardware, software or expertise. The Parkhill group pursues self-consistent methods for studying non-equilibrium quantum electronic dynamics using dynamical embeddings that provide a common framework to treat extended systems, correlation, and vibronic effects. These tools fluidly expand the standard toolbox of molecular quantum mechanics into a regime where electronic states are statistically mixed. A self-consistent beyond mean-field correlated dynamics method is being developed to study the interplay between electron correlation and decoherence. The Parkhill group?s realtime transient absorption technique is being generalized to reproduce coherent multidimensional experiments. These new tools are used to produce real-time simulations of photo-induced charge separation that feature an accurate treatment of quantum correlation effects, thermalization, and the environmental surroundings of a molecule. These simulations shed light on the mechanisms controlling plasmonic generation of hot electrons and charge separation in photovolatics. Embedded dynamics methodology complements existing approaches by providing a unified and systematically improvable platform for studying electronic dynamics in condensed systems.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.