Institute for Drug Research, School of Pharmacy, Ein Kerem Campus, The Hebrew University of Jerusalem, Jerusalem 9112001, Israel.
J Chem Theory Comput. 2023 Jun 13;19(11):3102-3111. doi: 10.1021/acs.jctc.2c01000. Epub 2023 May 15.
The valence bond (VB) theory uses localized orbitals, and its wave function is composed of a linear combination of various VB structures which are based on sets of spin functions. The VB structures are not unique, and different sets are used, Rumer sets being the most common for classical VB due to their advantage as being both easily obtained as linearly independent and meaningful. Yet, Rumer rules, which are responsible for the simplified process of obtaining the Rumer sets, are very restrictive. Furthermore, Rumer sets are best suited for cyclic systems; however, in noncyclic systems, structures resulting from Rumer rules are often not the most intuitive/suitable structures for these systems. We have developed a method to obtain chemically insightful structures, which is based on concepts of chemical bonding. The method provides sets of VB structures with improved chemical insight, which can also be controlled. Parallel to the Rumer structures, the chemical insight sets of structures are based on electron pair coupling, and hence, pictorially can be drawn similarly to the Lewis structures. Yet, different from Rumer rules, the chemical insight method, being more flexible, allows larger combinations of bonds as well as larger combinations of structures in the sets it offers, resulting in many more possible sets that are better adapted to the systems studied.
价键理论（VB 理论）使用局域轨道，其波函数由基于自旋函数集的各种 VB 结构的线性组合构成。VB 结构不具有唯一性，并且使用不同的集合，由于其作为线性独立且有意义的集合的优势，Rumer 集合是经典 VB 中最常用的集合。然而，负责简化获得 Rumer 集合的 Rumer 规则非常严格。此外，Rumer 集合最适合于循环系统；然而，在非循环系统中，Rumer 规则产生的结构通常不是这些系统最直观/合适的结构。我们开发了一种基于化学键概念获得具有增强的化学洞察力的结构的方法。该方法提供了具有改进的化学洞察力的 VB 结构集，并且这些结构集还可以进行控制。与 Rumer 结构类似，化学洞察结构集基于电子对耦合，因此，可以以类似于路易斯结构的方式进行图像描绘。然而，与 Rumer 规则不同，化学洞察方法更加灵活，允许更大的键组合以及它提供的结构的更大组合，从而产生了更多更好地适应所研究系统的可能结构集。
