化学反应过渡态控制着化学反应的速率、产物的通道分支比和量子态分布。直接观测化学反应过渡态是化学研究的圣杯之一。光电子-光解碎片符合谱技术通过同时测量负离子光致脱附过程中光电子的动能和光解碎片的平动能以及其标量相关，直接成像反应过渡态的动力学过程，是研究反应过渡态的一种非常重要的手段。本项目拟采用全维量子动力学方法，理论模拟多原子分子体系（NH4和H3O2）的光电子-光解碎片符合谱，通过比对实验光谱测量，验证势能面的精度，并追踪波包演化过程，解释瞬态中间物的解离机制，为理解基元化学反应提供更直接、更详细的信息，加深对化学反应本质的认识。

The kinetic and dynamic quantities of chemical reactions, such as rate constant, branching ratio and energy distribution of product molecules, are predominated by their individual transition states. The direct observation of the transition state for chemical reaction is devoted to the “Holy Grail” of chemistry. A very powerful tool to image the dynamical process of transition state is photoelectron-photofragment coincidence (PPC) spectroscopy, which measures the kinetic energies of photoelectron and photofragment in coincidence and the correlation between them. Within a full-dimensional quantum mechanical model, the experimental PPC spectra of polyatomic systems NH4 and H3O2 will be simulated by quantum wave packet method. On one hand, the accuracy of potential energy surfaces can be assessed by comparing the theoretical and experimental spectra. On the other hand, studies on the evolution of the quantum wave packet help us explain the dissociative mechanism of transient neutral species, provide us more direct and detailed information, deepen our understanding of chemical reactions.