Is Unified Understanding of Vibrational Coupling of Water Possible? Hyper-Raman Measurement and Machine Learning Spectra
Is Unified Understanding of Vibrational Coupling of Water Possible? Hyper-Raman Measurement and Machine Learning Spectra
复制标题
对水振动耦合的统一理解可能吗？
DOI：
10.1021/acs.jpclett.3c00398
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发表时间：
2023
期刊：
影响因子：
--
通讯作者：
Okuno Masanari
中科院分区：
文献类型：
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作者：
Inoue Kazuki;Litman Yair;Wilkins David M.;Nagata Yuki;Okuno Masanari
OH伸缩模的振动耦合对光谱的影响在水的IR和拉曼光谱之间显著不同。对振动耦合的统一认识尚未实现。通过使用不同类别的振动光谱，超拉曼（HR）光谱，以及机器学习辅助的HR光谱计算，我们通过比较同位素稀释的H2O和纯H2O来研究水的振动耦合的影响。我们发现，同位素稀释降低HR带宽，但振动耦合的影响小于在IR和平行偏振拉曼。机器学习HR光谱表明，分子间耦合在加宽带宽方面起主要作用，而分子内耦合小得可以忽略，这与IR和拉曼光谱一致。我们的结果清楚地表明，分子内振动的影响有限，独立于振动光谱的选择规则。
The impact of the vibrational coupling of the OH stretch mode on the spectra differs significantly between IR and Raman spectra of water. Unified understanding of the vibrational couplings is not yet achieved. By using a different class of vibrational spectroscopy, hyper-Raman (HR) spectroscopy, together with machine-learning-assisted HR spectra calculation, we examine the impact of the vibrational couplings of water through the comparison of isotopically diluted H2O and pure H2O. We found that the isotopic dilution reduces the HR bandwidths, but the impact of the vibrational coupling is smaller than in the IR and parallel-polarized Raman. Machine learning HR spectra indicate that the intermolecular coupling plays a major role in broadening the bandwidth, while the intramolecular coupling is negligibly small, which is consistent with the IR and Raman spectra. Our result clearly demonstrates a limited impact of the intramolecular vibration, independent of the selection rules of vibrational spectroscopies.