Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, P.R. China.
Chemistry. 2018 Jul 5;24(38):9639-9650. doi: 10.1002/chem.201801220. Epub 2018 Jun 13.
Decomposing chemical interactions into bonds and other higher order interactions is a common practice to analyse chemical structures, and gave birth to many chemical concepts, despite the fact that the decomposition itself might be subjective in nature. Fragment molecular orbitals (FMOs) offer a more rigorous alternative to such intuition, but might be less interpretable due to extensive delocalisation in FMOs. Inspired by the Principal Component Analysis in statistics, we hereby present a novel framework, Principal Interacting Orbital (PIO) analysis, that can very quickly identify the "dominant interacting orbitals" that are semi-localised and easily interpretable, while still maintaining mathematical rigor. Many chemical concepts that are often taken for granted, but could not be easily inferred from other computational techniques like FMO analysis, can now be visualised as PIOs. We have also illustrated, through various examples covering both organic and inorganic chemistry, how PIO analysis could help us pinpoint subtle features that might play determining roles in bonding and reactions.
将化学相互作用分解为键和其他更高阶相互作用是分析化学结构的常见做法，并催生了许多化学概念，尽管这种分解本身在本质上可能是主观的。片段分子轨道（FMO）为这种直观提供了一种更严格的替代方法，但由于 FMO 中的广泛离域，可能不太容易解释。受统计学中主成分分析的启发，我们在此提出了一种新的框架，即主相互作用轨道（PIO）分析，可以非常快速地识别出“主要相互作用轨道”，这些轨道是半局部的，易于解释，同时仍保持数学严谨性。许多化学概念通常被视为理所当然，但无法从其他计算技术（如 FMO 分析）轻易推断出来，现在可以用 PIO 表示。我们还通过涵盖有机和无机化学的各种示例说明了 PIO 分析如何帮助我们发现可能在键合和反应中起决定性作用的细微特征。
