复杂多原子反应体系的态-态量子动力学研究

Quantum state-resolved reaction dynamics has attracted much attention as it can provide the most detailed microscopic dynamic mechanisms. At present, it is feasible to construct accurate potential energy surfaces and perform accurate quantum dynamics calculations for a direct polyatomic reaction with only one potential barrier, but it is of great challenges for a complex polyatomic reaction involving deep potential wells and multi-channels. In this proposal, we will develop the wavepacket dynamics method and computer code by using a hyperspherical coordinate system or a hybrid coordinate system combined with hyperspherical and internal coordinates, which can describe both reactant and product configuration spaces simultaneously, to decrease the number of basis functions significantly and improve computational efficiency remarkably. Based on the electronic structure calculations using the explicitly correlated version of the multi-reference configuration interaction method and fitted by a permutation invariant polynomial-neural network method, the global potential energy surfaces of the ground and excited states for a series of important multi-channel complex systems with deep wells, such as HO2, H3O, NH3, H2O2 and HO3, will be constructed including possible non-adiabatic couplings such as conical intersections and spin-orbital couplings. The applicability of the Gaussian process regression method will also be investigated in the potential fitting. We will obtain the state-to-state reaction dynamic information, explore the influence of the initial ro-vibrational states, collision energy, and the non-adiabatic effect on the reaction dynamics, and provide the detailed microscopic dynamic mechanisms.

量子态分辨的分子反应动力学因可提供详细微观机制而备受关注。目前，对于经过一个能垒进行的直接多原子反应，已可以构建高精度势能面并实现精确的量子动力学计算，然而，对于具有深势阱和多通道的复杂多原子反应，体系势能面构建和量子动力学计算仍很困难。本项目拟发展波包动力学方法和计算机程序，使用可同时较好描述反应物和产物构型空间的超球坐标系以及超球坐标与内坐标组合的混合坐标，显著提高计算效率。利用含显相关的多参考组态相互作用方法进行电子结构计算，再结合置换不变多项式-神经网络的势能面拟合方法，并探索高斯过程方法的适用性，构建系列重要的多通道和深势阱的复杂反应体系如HO2、H3O、NH3、H2O2和HO3等电子基态和低激发态的全域势能面，并考虑电子态之间的非绝热耦合如锥形交叉和旋轨耦合等，获得详细的态－态动力学性质，探索初始振转态及非绝热效应等对反应动力学的影响，揭示细致的微观动力学机制。

量子态分辨的分子反应动力学因可提供详细的微观机制而备受关注。对于经过一个能垒进行的直接多原子反应，已可以构建高精度势能面并实现精确的量子动力学计算，然而，对于具有深势阱和多通道的复杂多原子反应，体系势能面构建和量子动力学计算仍很困难。本项目发展了针对三原子和四原子反应体系的基于超球坐标和混合坐标的产物量子态分辨的分子反应动力学理论计算方法和计算程序，即相互作用区-渐进区分解方法，显著提高了计算效率，有效克服了量子动力学中长期存在的“坐标难题”；针对2+2和3+1传能体系，发展了包含最近邻科里奥利耦合的全维非含时量子动力学计算方案和计算程序，并成功应用于HF+HF、H2O+Cl等体系的振动弛豫动力学研究；利用含显相关的多参考组态相互作用方法进行电子结构计算，结合置换不变多项式-神经网络与高斯过程回归等拟合方法，构建了系列重要的多通道和深势阱的复杂反应体系如HO2、IO2、HF+HF、HF+H2、HO3、H2O3、CH2OH和C2H2O等电子基态或激发态的全域势能面，并考虑电子态之间的非绝热耦合如锥形交叉和旋轨耦合等，通过量子动力学计算获得了详细的态－态动力学性质，探索初始振转态及非绝热效应等对反应动力学的影响，揭示了若干在星际化学、燃烧化学、大气化学和化学激光等领域中重要碰撞过程的细致的微观动力学机制。五年来，在国际重要学术期刊上共发表论文76篇，包括Science、Nature 各1篇（与实验合作）, Nat. Commun. 4篇，Sci. Adv. 1篇，J. Am. Chem. Soc. 2篇，J. Phys. Chem. Lett. 10篇，Phys. Chem. Chem. Phys. 8篇，J. Chem. Phys. 15篇等。13次受邀在国际国内学术会议上做邀请报告，培养了1名副教授并获优青资助以及14名博士研究生和4名博士后。