CAREER: Resonant Hartree-Fock Inspired Descriptions of Excited State Processes

路易斯维尔大学的Lee M.Thompson在化学系化学理论、模型和计算方法(CTMC)计划和刺激竞争研究(EPSCoR)计划的支持下，正在开发计算方法来模拟与金属光催化相关的激发态过程。金属光催化将过渡金属催化和光氧化还原催化相结合，使新的分子合成方法成为可能。然而，几种相互竞争的催化剂活化机制可能会导致不同的反应产物，因此计算模型有助于建立激发态过程的速率，并设计提高预期反应活性的催化体系。为此，存在建模挑战，包括：(I)所涉及的系统的大小，(Ii)这些系统的电子结构的性质，因为这些通常不服从简化的CPU(中央处理单元)时间方法中体现的当前近似，以及(Iii)需要计算难以从模拟中提取的项的理论形式。为了解决这些困难，汤普森博士正在开发一种计算方法，将低成本的近似方法结合在一起，每个近似方法都能捕捉到电子结构的不同特征。其目的是开发一个更准确的方法的通用计算平台，利用电子相互作用的划分来减少计算工作量。该项目还包括制定一项综合教育计划，侧重于编程素养和可持续软件开发，旨在使学生对物理化学和计算科学有更深的了解。首席研究员还在努力建立一个论坛，通过德比讲座系列吸引肯塔基州路易斯维尔化学企业的利益相关者。这个由哈特里-福克激发的共振描述激发态过程的项目包括两个主要的科学目标。首先，Thompson研究团队正在开发探索自洽场(SCF)解空间的算法，以了解SCF函数场景如何编码不同的关联机制。该方法允许枚举SCF解决方案，从中可以选择跨越分子系统中存在的相关关联机制的短行列式展开。此外，SCF解决方案可以作为后SCF方法的参考。其次，正在设计和实施优化different-orbitals-for-different-configurations波函数以考虑不同相关机制之间相互作用的模型。所得到的波函数被用作以降低的计算成本恢复剩余相关能量的平台。这些新方法将应用于金属光催化体系的光致电子转移和激发能量转移速率的研究。这些工具如果成功，可能会对新的光氧化还原催化剂系统和工艺的设计产生重大影响，这是目前反应开发中非常感兴趣的一个领域。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。

With support from the Chemical Theory, Models and Computational Methods (CTMC) Program in the Division of Chemistry and the Established Program to Stimulate Competitive Research (EPSCoR), Lee M. Thompson of University of Louisville is developing computational approaches to simulate excited state processes of relevance to metallo-photocatalysis. Metallo-photocatalysis combines transition metal catalysis and photoredox catalysis to enable new molecular synthesis approaches. However, several competing mechanisms for catalyst activation can potentially lead to different reaction products, and so computational modelling is beneficial to establish the rates of excited state processes and design catalytic systems that enhance the desired reactivity. For this, modeling challenges exist, including: (i) the size of the systems involved, (ii) the nature of the electronic structure of these systems as these are often not amenable to current approximations embodied in reduced-CPU (central processing unit) time methods, and (iii) theoretical formalisms requiring computation of terms that are difficult to extract from simulation. To resolve these difficulties, Dr. Thompson is developing computational methods that couple together low-cost approximations that each capture different features of the electronic structure. The aim is to develop a general computational platform of more accurate approaches that takes advantage of partitioning of the electronic interactions to reduce computational efforts. This project also includes the development of an integrated education plan focusing on programming literacy and sustainable software development that aims to provide students with a deeper understanding of physical chemistry and computational science. The principal investigator is also working to build a forum to engage stakeholders in the chemistry enterprise in Louisville, KY through the Derby lecture series. This project on Resonant Hartree-Fock inspired descriptions of excited state processes consists of two main scientific goals. First, the Thompson research team is developing algorithms that explore self-consistent field (SCF) solution space to understand how the SCF function landscape encodes different correlation mechanisms. The methods permit enumeration of SCF solutions from which a short determinant expansion can be chosen that spans relevant correlation mechanisms present in molecular systems. Additionally, the SCF solutions can be used as references for post-SCF methods. Second, models that optimize a different-orbitals-for-different-configurations wavefunction to account for interactions between the different correlation mechanisms are being designed and implemented. The resulting wavefunction is being used as a platform to recover remaining correlation energy at reduced computational cost. The new methods will be applied to the study of photo-induced electron transfer and excitation energy transfer rates in metallo-photocatalytic systems. These tools, if successful, could have a significant impact on the design of new photoredox catalyst systems and processes, an area of great current interest in reaction development.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.