RUI: A Theoretical Investigation of Multireference Diradical Molecules

里士满大学的卡罗尔教区获得了理论和计算化学项目的本科院校研究奖，用于对涉及自由基中间体的环化反应进行理论研究。 本文的工作主要集中在以下几个方面：1）自旋翻转、单重态强正交Geminal（SSG）、多参考平均二次耦合团簇（MR-AQCC）和完全重整化耦合团簇的应用和比较（CR-CC（2，3））方法描述双自由基的多参照特征、能量和结构; 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）使用基于力场的混合MonteCarlo-Low Mode构象分析方法来评估较大天然产物双自由基前体的结构系综; 5）开发使用Kohonen的自组织映射来评估系综的几何聚类性质的算法; 6）使用KNIME脚本语言提供“包装器”，以方便大学生使用这些方法。壳自由基物质和相应的新型环化反应的研究对于推进多参考理论化学领域具有重要的前景，机械有机化学、材料设计和药物优化。这项工作有助于进一步了解激进行为，并有望对这些应用领域产生积极影响。这项工作是由本科研究人员早在他们的第一年学习。学生们正在接受计算化学的强化培训，并从这一经验，正在开发的技能集，这将有助于他们在他们的后学士学位的科学生涯。 PI是MERCURY联盟的创始成员，该联盟旨在指导其他以本科为主的机构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MERCURY的活动，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.