RUI: A Theoretical Investigation of Multireference Diradical Molecules

里士满大学的卡罗尔·帕里什（Carol Parish）因对涉及自由基中间体的环化反应进行理论研究而获得了理论与计算化学项目的本科院校研究奖（RUI）。1)利用自旋翻转、单重态强正交双基（SSG）、多参考平均二次耦合簇（MR-AQCC）和完全重整化耦合簇（CR-CC(2,3)）等方法描述双基的多参考特征、能量和结构，并进行了比较；2)将这些方法中的一种或多种应用于涉及双自由基中间体的新型电环化反应的表征；3)研究涉及四自由基的反应；4)采用基于力场的混合Monte Carlo-Low模式构象分析方法对较大天然产物二自由基前体的结构系综进行评价；5)开发利用Kohonen自组织映射评价集合几何聚类性质的算法；6)使用KNIME脚本语言提供“包装器”，方便本科生使用这些方法。正确表征开壳自由基的能力以及对新型环化反应的相应研究对于推进多参比理论化学、机械有机化学、材料设计和药物优化等领域具有重要的前景。这项工作有助于进一步了解自由基的行为，并有望对这些应用领域产生积极影响。这项工作是由本科生研究人员在他们第一年的学习中进行的。学生们正在接受计算化学方面的强化训练，并从这种经验中培养技能，这些技能将很好地为他们毕业后的科学事业服务。PI是水星联盟的创始成员，该联盟旨在指导其他主要本科院校的新计算和理论化学教师实现卓越的教学和研究。参与该项目的学生正在参加水星活动，进一步扩大了该项目的影响。

Carol Parish of the University of Richmond is supported by a Research in Undergraduate Institutions (RUI) award from the Theoretical and Computational Chemistry program for theoretical investigations of cyclization reactions involving radical intermediates. The work is focused on 1) Utilizing and comparing the Spin-Flip, Singlet-type Strongly Orthogonal Geminal (SSG), Multireference Averaged-Quadratic Coupled Cluster (MR-AQCC) and Completely Renormalized Coupled Cluster (CR-CC(2,3)) methods for describing the multireference character, energies and structures of diradicals; 2) Applying one or more of these methods to the characterization of novel electro-cyclization reactions involving diradical intermediates; 3) Investigating reactions involving tetraradicals; 4) Using the force field based hybrid Monte Carlo-Low Mode method of conformational analysis to evaluate the ensemble of structures for larger natural product diradical precursors; 5) Developing algorithms for using Kohonen's self-organizing map to evaluate the geometrical clustering properties of ensembles, and; 6) Employing the KNIME scripting language to provide "wrappers" to facilitate the use of these methods by undergraduates.The ability to characterize properly open-shell radical species and the corresponding investigation of novel cyclization reactions holds significant promise for advancing the fields of multireference theoretical chemistry, mechanistic organic chemistry, materials design and drug optimization. This work is contributing to furthering understanding of radical behavior and is expected to positively impact these fields of application. The work is being performed by undergraduate researchers as early as their first year of study. The students are receiving intensive training in computational chemistry, and, from this experience, are developing skill sets that will serve them well in their post-baccalaureate scientific careers. The PI is a founding member of the MERCURY consortium which was designed to mentor new computational and theoretical chemistry faculty at other predominately undergraduate institutions in achieving teaching and research excellence. Students involved in this project are participating in MERCURY activities, further broadening the impact of this project.