Wavepacket Dynamics of Ultrafast Chemical Processes

1. 利用二次啁啾脉冲对O+H光结合反应进行波包计算，实现了产物OH分子的振动冷却。啁啾相干拉曼光谱：在二阶微扰理论的基础上，导出了描述啁啾激光脉冲存在下分子系统的自发和受激拉曼散射的解析公式。3 .氧化Si（100）表面Xe的光激解吸：为了阐明光激解吸的机理，对Xe/氧化Si（100）系统在电子基态和激发态的势能面进行了从头算CASSCF计算，并基于波包计算分析了光激解吸的平动能量分布。量子速率常数的通量-通量互相关函数方法：我们采用通量-通量互相关方法（CCFA）来计算自相关函数方法（ACFA）不足以应用的反应的量子热速率常数，封闭划分曲面和CCFA的组合给出了单跳率和多跳率的定义良好的速率常数。松弛条件下的种群迁移：种群完全反转的实现是控制的一种。在这项研究中，我们发现比正啁啾效应对激光持续时间更重要的机制可以任意确定和选择啁啾速率。这一结论表明，在超快弛豫存在的情况下，有可能发生完全的种群反转。

1. Molecular Vibrational Cooling via Photoassociation Process :Wavepacket calculations on the O+H photoassociation reaction with a quadratic-chirped pulse have achieved the vibrational cooling of the product OH molecule.2. Chirped Coherent Raman Spectroscopy :On the basis of a second-order perturbation theory, analytical formulas are derived for describing spontaneous and stimulated Raman scatterings of a molecular system in the presence of chirped laser pulse.3. Photo-stimulated Desorption of Xe from an Oxidized Si(100) Surface :Ab initio CASSCF calculations for the potential energy surfaces of the Xe/oxidized Si(100) system in the electronic ground and excited states are performed in order to clarify the mechanism of photo-stimulated desorption and the translational energy distribution is analyzed based on wavepacket calculations.4. Flux-Flux Cross-Correlation Function Approach to Quantum Rate Constants :We employ a flux-flux cross-correlation approach (CCFA) to calculate quantum thermal rate constants of reactions to which an auto-correlation function approach ACFA) is not adequate to be applied, A combination of closed dividing surfaces and CCFA gives well-defined rate constants for both single and multi-hopping rates.5. Population Transfer in the Presence of Relaxation :Achievement of complete population inversion is one of control. In this study, we found that the mechanism important than that of positive-chirp effect for duration of a laser can be arbitrarily determined and chirp rate are chosen. This conclusion demonstrates a possibility of complete population inversion in the presence of ultrafast relaxation.