The relaxation mechanism of the overtone bending vibration in the collision of the water dimer with the vibrationally excited hydroxyl radical is studied by use of trajectory procedures. The transfer of the OH(v = 1) energy to the dimer stretches is followed by a near-resonant first overtone transition to the donor monomer. Nearly a quarter of the trajectories undergo a complex-mode collision, forming the (H₂O)₂···OH complex bound by a hydrogen bond with the lifetime ranging from a subpicosecond scale to >100 ps. The overtone vibration relaxes to the ground state, transferring approximately half of its energy to the dimer hydrogen-bonding (H₂O···H₂O) and the remaining half to the complex hydrogen-bonding (H₂O)₂···OH, via near-resonant pathways, each consisting of a series of intermolecular low-frequency vibrations.

中文翻译：

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水二聚体···羟基自由基络合物中H ₂ O泛音弯曲振动的弛豫

利用轨迹程序研究了水二聚体与振动激发的羟基自由基碰撞时泛音弯曲振动的弛豫机理。OH（v = 1）能量转移到二聚体链段之后，是接近共振的第一泛音跃迁到供体单体。近四分之一的轨迹经历了复模碰撞，形成了由氢键结合的（H ₂ O）₂ ···OH络合物，其寿命范围从亚皮秒级到> 100 ps。泛音振动松弛到基态，大约一半的能量转移到二聚体氢键（H ₂ O··H ₂ O），剩余的一半转移到复氢键（H ₂O）₂ ···OH，通过近共振路径构成，每个路径由一系列分子间低频振动组成。