Raman spectroscopy of isotopically pure and diluted high‐ and low‐density amorphous ices
Raman spectroscopy of isotopically pure and diluted high‐ and low‐density amorphous ices
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纯同位素和稀释的高密度和低密度非晶冰的拉曼光谱
DOI：
10.1002/jrs.6322
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发表时间：
2022
影响因子：
2.5
通讯作者：
Yamaguchi Shoichi
中科院分区：
文献类型：
--
作者：
Ishihara Senri;Takayama Tetsuyuki;Sakaguchi Miyuki;Otosu Takuhiro;Yagasaki Takuma;Suzuki Yoshiharu;Yamaguchi Shoichi
我们给出了在30 K下同位素纯和稀释的非晶态以及晶态冰的拉曼光谱的实验和理论研究。我们的实验包括在OH伸展区域的极化(VV)和去极化(VH)光谱，而我们的计算涉及通过玻璃化以及随后在冰的氢键网络中耦合的OH振子的振动哈密顿量的公式来模拟高密度和低密度的非晶冰。在每个同位素稀释度下，我们的理论拉曼光谱、VV谱和VH谱与实验数据符合得很好。这不仅使我们能够从振相、离域和态密度的角度对非晶态和晶态冰进行详细的光谱指认，而且还可以证实MD模拟的可靠性，在液液临界点以下，深度过冷的液态水自发地分成高密度和低密度的流体相。
We present an experimental and theoretical study of Raman spectroscopy of isotopically pure and diluted amorphous as well as crystalline ices at 30 K. Our experiments comprise polarized (VV) and depolarized (VH) spectra in the OH‐stretch region, whereas our calculations involve molecular dynamics (MD) simulation of the high‐ and low‐density amorphous ices through vitrification and subsequent formulation of vibrational Hamiltonian of coupled OH oscillators in the hydrogen‐bond network of the ices. Our theoretical Raman VV and VH spectra at each isotopic dilution are in good agreement with the experimental data. This allows us not only to carry out detailed spectral assignments for the amorphous and crystalline ices from the viewpoint of vibrational phase, delocalization, and density of states but also to confirm the reliability of the MD simulation in which deeply supercooled liquid water spontaneously separates into high‐ and low‐density fluid phases below a liquid–liquid critical point.