单分子体系中氢迁移单量子态的量子力学研究

H-migration is of vital importance in the field of chemistry and chemical biology, but this kind of process remains poorly understood. In our recent accurate full-dimensional quantum mechanical calculations, we found that there exists vinylidene-acetylene H-migration single quantum-state, which is a kind of delocalized "vibrational" quantum-state. It has large and similar probability density distributions in the regions of acetylene and vinylidene. The project intends to study this single quantum-state and its interaction deeply and systematically using quantum mechanical methods, and also to extend the similar studies to other H-migration systems (such as HFCO and C3H4O2). We will use the highly efficient quantum mechanical methods and parallel computing programs developed by us. It is expected that we will acquire more accurate quantum dynamical understanding of H-migration processes, and find a few novel quantum effects. At the highly accurate ab initio potential energy surface and quantum dynamical level, we will elaborate the characteristics and laws of the H-migration quantum-state phenomenon, and give the interpretation and guidance for the relevant experiments. The findings not only has academic significance, but also has important values in revealing the essential characteristics of isomerizing systems like vinylidene-acetylene and understanding the mechanisms of H-migration processes at the single quantum-state level.

氢迁移反应过程在化学和化学生物学领域是至关重要的，但目前人们对这种过程的认识还很不够。我们最近通过精确全维量子计算发现存在亚乙烯基-乙炔氢迁移单量子态，这是一种在乙炔和亚乙烯基区域都有很大且相近的几率密度分布的离域“振动”单量子态。本项目拟对这种单量子态及相互作用开展深入系统的量子力学研究，也拟将类似研究扩展到其它重要氢迁移体系(如HFCO和C3H4O2)，将使用我们发展的高效量子力学方法及并行化的计算程序。可望获得对氢迁移过程的更准确的量子动力学认识，和发现若干新奇量子效应。将在高精度从头算势能面和量子动力学的层次上，阐明氢迁移单量子态现象的特征和规律，并解释和指导相关的实验。研究结果不仅具有显著的学术意义，而且对于揭示亚乙烯基-乙炔等异构体系的本质特征，在单量子态水平上理解氢迁移过程的机理具有重要的价值。

氢迁移反应过程在化学和化学生物学领域是至关重要的，但目前人们对这种过程的认识还很不够。本项目通过精确全维量子力学计算对亚乙烯基-乙炔体系中的氢迁移单量子态及相互作用开展了深入系统的研究，实现了对分步双氢迁移反应的选模隧穿分裂的精确量子计算, 获得了对隧穿增强的氢迁移单量子态之间相互作用的新认识，计算中使用了我们发展的高效量子力学方法及并行化的计算程序，代表性论文发表在J.Phys.Chem.Lett.。同时，将类似研究扩展到了其它重要涉氢体系(如C3H4O2和CH2)，获得了对氢迁移过程的更准确的量子动力学认识，发现了若干有趣的量子效应。例如,通过在我们构建的高精度从头算势能面上的精确量子力学计算揭示出尖锐而密集的动力学共振,而这导源于存在大量亚稳的亚甲基单量子振转态，我们还发现分波单量子态之间的干涉行为(或相互作用)引起了角分布随散射角的振荡结构。我们在高精度从头算势能面和量子动力学的层次上阐明了涉氢量子效应的一些特征和共性，并解释和指导了相关的实验。研究结果不仅具有重要的学术意义，而且对于揭示亚乙烯基-乙炔等异构体系的本质特征，在单量子态水平上理解氢迁移过程的机理具有重要的价值。