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

该奖项全部或部分由2021年美国救援计划法案（公法117-2）资助。在化学系化学理论、模型和计算方法项目的支持下，科罗拉多大学博尔德分校的Sandeep Sharma正在开发计算理论和方法，以推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系统;这种催化剂是制药工业和能量转换领域中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，从鸟类通过磁感受器导航到小分子的酶催化氧化还原反应。其他现象包括具有与量子信息科学（QIS）相关的量子态的材料。产生这些显著性质的基本微观原理通常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，因为后者可能过于昂贵，有时极难进行。 然而，执行这样的“数值实验”远非微不足道，本提案的目标是克服这一挑战。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。这些发展将在两类系统上得到验证：（1）当含铜催化剂/酶进行O2活化，然后通过C-H键断裂进行底物氧化时，Cu-O络合物是重要的中间体;（2）含有铱原子并显示奇异量子态的过渡金属氧化物。为了使该项目产生更广泛的影响，Sharma小组将向化学界提供新开发的软件，并创建新的教育材料，介绍量子化学和软件实施的基础知识。在外联方面，Sharma博士将参与美非合作框架下的教育和培训活动。Sandeep Sharma和他的研究小组将设计新的电子结构算法，该算法将联合收割机技术从量子蒙特卡罗，多参考量子化学和张量网络方法中借用，以显着提高我们表征强相关系统的能力。这些算法将用于表征两类代表性体系的物理/化学：（1）Cu-O络合物，其是含铜催化剂/酶进行O2活化接着底物氧化，特别是C-H键断裂时的重要中间体;（二）铱酸盐是含有铱原子的过渡金属氧化物，通过电子相关性之间的竞争，和自旋轨道耦合;这些是用于承载拓扑保护的容错量子态的候选者。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，并创建新的教育材料，涉及量子化学和软件实施的基础知识。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）开展工作，通过在撒哈拉以南非洲教授课程进行国际推广。这不仅有助于教育早期职业生涯的学生的颜色，但也将提供一个机会，吸引一些非常有才华的学生在美国攻读博士学位。这个奖项反映了NSF的法定使命，并已被认为是值得通过使用基金会的智力价值和更广泛的影响审查标准进行评估的支持。

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.