The vibrational spectroscopy of the water dimer provides an understanding of basic hydrogen bonding in water clusters, and with about one water dimer for every 1,000 water molecules, it plays a critical role in atmospheric science. Here, we review how the experimental and theoretical progress of the past decades has improved our understanding of water dimer vibrational spectroscopy under both cold and warm conditions. We focus on the intramolecular OH-stretching transitions of the donor unit, because these are the ones mostly affected by dimer formation and because their assignment has proven a challenge. We review cold experimental results from early matrix isolation to recent mass-selected jet expansion techniques and, in parallel, the improvements in the theoretical anharmonic models. We discuss and illustrate changes in the vibrational spectra of complexes upon increasing temperature, and the difficulties in recording and calculating these spectra. In the atmosphere, water dimer spectra at ambient temperature are crucial.

中文翻译：

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喷射冷却和大气温度下水二聚体的振动光谱

水二聚体的振动光谱可以帮助我们了解水簇中的基本氢键，每 1000 个水分子中就有一个水二聚体，它在大气科学中发挥着至关重要的作用。在这里，我们回顾了过去几十年的实验和理论进展如何提高了我们对寒冷和温暖条件下水二聚体振动光谱的理解。我们重点关注供体单元的分子内 OH 拉伸转变，因为这些是最受二聚体形成影响的转变，而且它们的分配已被证明是一个挑战。我们回顾了从早期矩阵隔离到最近的质量选择射流膨胀技术的冷实验结果，同时回顾了理论非谐模型的改进。我们讨论并说明了配合物振动光谱随温度升高的变化，以及记录和计算这些光谱的困难。在大气中，环境温度下的水二聚体光谱至关重要。