CAREER: High Accuracy Methods for Electronic Structure of Molecules and Materials

该奖项的全部或部分资金来自《2021年美国救援计划法案》(公法117-2)。在化学系化学理论、模型和计算方法计划的支持下，科罗拉多大学博尔德分校的桑迪普·夏尔马正在开发计算理论和方法，以促进分子和材料电子结构的表征。特别令人感兴趣的是含有过渡金属原子簇的体系；这种催化剂是制药业和能源转换领域许多关键过程的核心。这些系统产生了与生物学相关的迷人现象，例如，从通过磁感受器的鸟类导航到酶催化的小分子氧化还原反应。其他现象包括与量子信息科学(QIS)相关的具有量子态的材料。导致这些显着特性的基本微观原理往往没有得到很好的理解和/或表征。获得更好理解的一个途径是进行“数值实验”，而不是实验室实验，因为后者可能太昂贵，有时甚至非常难以进行。然而，进行这样的“数值实验”绝非轻而易举，这项提议的目标就是克服这一挑战。为此，夏尔马博士和他的研究小组将开发理论、方法和计算机软件，使这些数值实验成为可能。这些进展将在两类系统上得到验证：(1)含铜催化剂/酶在氧活化后通过C-H键断裂进行底物氧化时，作为重要中间体的铜-氧配合物；(2)含有Ir原子并显示奇异量子态的过渡金属氧化物。对于该项目的更广泛影响，Sharma小组将向化学界提供新开发的软件，并创建处理量子化学基础和软件实施的新教育材料。在外展方面，夏尔马博士将参与美非合作框架下的教育和培训活动。桑迪普·夏尔马和他的研究小组将设计新的电子结构算法，结合借用量子蒙特卡罗、多参考量子化学和张量网络方法的技术，显著提高我们表征强关联系统的能力。这些算法将被用来表征两类代表性系统的物理/化学：(1)当含铜的催化剂/酶执行O2活化随后底物氧化，特别是C-H键断裂时，铜-O络合物是重要的中间体；(2)Irate，它是包含Ir原子的过渡金属氧化物，并在电子关联和自旋轨道耦合之间的竞争中显示出奇异的量子态；这些是拥有拓扑保护的容错量子态的候选对象。在更广泛的影响领域，Sharma小组将向化学界提供新开发的软件，并创建处理量子化学基础和软件实施的新教育材料。此外，PI计划通过USAfri(美国-非洲电子结构倡议)和ASESMA(非洲电子结构方法和应用学校)开展国际推广，在撒哈拉以南非洲教授课程。这不仅将有助于培养有色人种的早期职业学生，还将提供一个机会，吸引一些才华横溢的学生来美国攻读博士学位。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。

This award is funded in whole or in part under the American Rescue Plan Act of 2021 (Public Law 117-2).WIth support from the Chemical Theory, Models and Computational Methods Program in the Division of Chemistry, Sandeep Sharma of the University of Colorado at Boulder is developing computational theories and methods to advance the characterization of the electronic structure of molecules and materials. Of specific interest are systems that contain clusters of transition metal atoms; such catalysts are at the heart of many critical processes in the pharmaceutical industry and in the area of energy conversion. These systems give rise to fascinating phenomena that are relevant in biology for example, from bird navigation via magnetoreceptors to enzyme-catalyzed redox reaction of small molecules. Other phenomena include materials with quantum states relevant to Quantum Information Science (QIS). The underlying microscopic principles giving rise to these remarkable properties are often not well understood and/or characterized. One avenue of obtaining a better understanding is to perform "numerical experiments" instead of laboratory experiments, as the latter, may be too expensive and sometimes extremely difficult to conduct. However, performing such "numerical experiments" is far from trivial and the goal of this proposal is to overcome this challenge. To this end, Dr. Sharma and his research group will develop theories, methods, and computer software that will enable these numerical experiments. These developments will see their validation on two classes of systems: (1) Cu-O complexes that are important intermediates when copper containing catalysts/enzymes perform O2 activation followed by substrate oxidation via C-H bond breaking; (2) transition metal oxides that contain iridium atoms and display exotic quantum states. For broader impacts of the project, the Sharma group will make the newly developed software available to the chemistry community and create new educational materials dealing with the fundamentals of quantum chemistry and software implementation. For outreach, Dr. Sharma will be involved in education and training activities under a US-Africa collaboration framework. Sandeep Sharma and his research group will devise novel algorithms of electronic structure that combine techniques borrowed from quantum Monte Carlo, multi-reference quantum chemistry, and tensor network methods to significantly advance our ability to characterize strongly correlated systems. These algorithms will be used to characterize the physics/chemistry of two classes of representative systems: (1) Cu-O complexes that are important intermediates when copper containing catalysts/enzymes perform O2 activation followed by substrate oxidation, in particular C-H bond breaking; (2) Iridates that are transition metal oxides that contain iridium atoms and display exotic quantum states facilitated by a competition between electron correlation and spin orbit coupling; these are candidates for hosting topologically protected fault-tolerant quantum states. In the area of broader impacts, the Sharma group will make the newly developed software available to the chemistry community and create new educational material dealing with the fundamentals of quantum chemistry and software implementation. In addition, the PI plans to work through USAfri (US-Africa Initiative in Electronic Structure) and ASESMA (African School on Electronic Structure Methods and Applications) to do international outreach by teaching courses in sub-Saharan Africa. This will not only help educate early career students of color, but will also provide an opportunity to attract some highly talented students to pursue their PhD studies in the US.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.