Periodic Coupled Cluster Methods for Optical Activity in Chiral Crystals

在化学系化学理论、模型和计算方法项目的支持下，堪萨斯大学的Marco Caricato将致力于开发精确的量子力学方法来模拟固体对外部场的电子响应，并直接应用于光学活性。这些方法有望为手性材料的这一重要电子性质提供高度精确的数据，有两个目标：了解分子间相互作用对这一性质的难以捉摸的影响，并对近似但计算效率高的方法进行基准测试和改进。Caricato还将开发结构-性能关系的解释工具，这可能有助于定义具有所需特征的材料的设计原则。这些工具将用于开发减少缩放的策略，以提高计算效率。这个提议的更广泛的影响取决于计算化学的使用，以造福社会在技术进步和教育机会方面。对材料的手性响应的深入了解可能会导致设计原则的合理设计具有所需性能的材料的目标应用领域，如手性传感和电子。Caricato还将开发一项推广计划，以开发量子化学模拟在高中教育中的巨大潜力。Caricato将与当地高中教师合作，开发教育模块，让学生积极运行模拟并分析结果。这项计划有望激发堪萨斯州农村和经济落后地区的高中生对科学的热情，并激励他们继续接受STEM（科学、技术、工程和数学）学科的进一步培训。根据该合同，Caricato团队将开发用于晶体固体的线性响应-周期耦合簇（LR-PCC）方法，以及用于数据解释和降低计算成本的张量分解分析。尽管密度泛函理论（DFT）方法仍然代表了固态计算成本和准确性之间的巨大妥协，但它们仍然存在与分子相同的缺点：结果的质量依赖于系统，单个泛函不能系统地改进。尤其有问题的是分子间相互作用的描述，这是手性体系在凝聚相中整体光学响应的基础。提出的LR-PCC方法将提供关于分子间相互作用对固体光学活性作用的准确数据，以及为开发针对该性质的功能和基集提供基准数据。同时，对相关张量进行定性分析的新方法将被开发出来，这可能有助于解开光学活性材料中难以捉摸的结构-性质关系。这些方法还将用于设计减少缩放的技术，以提高算法的计算效率。这些努力有可能导致通用的方法，可以应用于固体的光学活性以外的其他电子性质。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值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 program in the Division of Chemistry, Marco Caricato of the University of Kansas will work to develop accurate quantum mechanical methods to simulate the electronic response of solids to external fields, with a direct application to optical activity. These methods are expected to provide highly accurate data for this important electronic property of chiral materials, with a twofold goal: to understand the elusive effect of intermolecular interactions on this property, and to benchmark and improve approximate but computationally efficient methods. Caricato will also develop interpretative tools for structure-property relations that may help define design principles for materials with desired features. These tools will be used to develop reduced-scaling strategies to increase computational efficiency. The broader impact of this proposal hinges on the use of computational chemistry to benefit society both in terms of technological advances and educational opportunities. A deeper understanding of the chiral response of a material may lead to design principles for the rational design of materials with desired properties for targeted applications in growing research fields such as chiral sensing and electronics. Caricato will also develop an outreach initiative to exploit the enormous potential of quantum chemistry simulations for high school education. In collaboration with local high school teachers, Caricato will develop educational modules where the students actively run the simulations and analyze the results. This initiative will hopefully stimulate the enthusiasm for science of high school students in rural and economically disadvantaged areas of the state of Kansas, and inspire them to pursue further training in STEM (science, technology, engineering and mathematics) disciplines. Under this award, the Caricato team will develop linear response-periodic coupled cluster (LR-PCC) methods for crystalline solids, and a tensor decomposition analysis useful for data interpretation as well as computational cost reduction. Although density functional theory (DFT) methods still represent a great compromise between cost and accuracy for solid state calculations, they still suffer from the same drawbacks as for molecules: the quality of the results is system-dependent and individual functionals are not systematically improvable. Particularly problematic is the description of intermolecular interactions, which are fundamental for the overall optical response of a chiral system in the condensed phase. The proposed LR-PCC methods will provide accurate data on the role of intermolecular interactions on the optical activity of solids as well as benchmarking data for the development of functionals and basis sets tailored for this property. At the same time, new approaches for qualitative analysis of the relevant tensors will be developed that may help unravel the elusive structure-property relations in optically active materials. These approaches will be also used to devise reduced-scaling techniques to increase the computational efficiency of the algorithms. These efforts have the potential to lead to general methodologies that can be applied to other electronic properties of solids beyond optical activity.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.