Tetrahedral structure of supercooled water at ambient pressure and its influence on dynamic relaxation: Comparative study of water models
Tetrahedral structure of supercooled water at ambient pressure and its influence on dynamic relaxation: Comparative study of water models
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常压过冷水的四面体结构及其对动态弛豫的影响：水模型的比较研究
DOI：
10.1016/j.molliq.2021.117269
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发表时间：
2021
影响因子：
6
通讯作者：
SAITO Shinji
中科院分区：
文献类型：
--
作者：
KUO Yu-Wei;TANG Ping-Han;WANG Hao;WU Ten-Ming;SAITO Shinji
本文通过比较TIP 4P/2005和SPC/E水模型的模拟结果，研究了常压下过冷水的四面体结构及其对动力学弛豫的影响。O原子径向分布函数g（r）具有第二个最大值和第一个最小值，结构因子的前两个峰的大小顺序相反，表明过冷水具有整体四面体结构.局部四面体结构是由分子指定的，这些分子及其邻居直到第二水化层都有四个氢键配位体。这些分子被称为低密度液体（LDL），其他分子被称为高密度液体（HDL）。通过自中间散射函数、非高斯参数和极化率各向异性时间相关函数研究了水动力学弛豫。我们的模拟表明，描述α-弛豫的拉伸指数的温度依赖性在Widom线（WL）以上的过冷区显示出一个小峰，其中LDL在峰值温度下约为总数的四分之一。描述极化率各向异性弛豫的拉伸指数被发现对温度不敏感，与实验结果一致。在WL以上，研究的所有弛豫时间均表现出幂律温度依赖性，并且每个模型的奇异温度一致。弛豫时间的倒数表现出指数函数的两体过剩熵，由于平移运动，熵表现出对数温度行为的奇异温度接近的弛豫时间。这一结果表明，在模式耦合理论适用的热力学区域内，过剩熵是描述过冷水动力学弛豫的一个量。水的结构，导致两体过剩熵的说明和HDL，LDL的贡献，以及它们的混合也显示，其中的混合贡献显着附近的WL。在WL以下，基于二体过剩熵的公式可能不再有效。
In this paper, we investigated the tetrahedral structure of supercooled water at ambient pressure and its influence on dynamic relaxation by comparing simulation results of TIP4P/2005 and SPC/E water models. The globally tetrahedral structure of supercooled water was characterized with the second-peak maximum and a deep first minimum in the radial distribution function g (r) of O-atoms and the reverse order in magnitude between the first two peaks of structure factor. The locally tetrahedral structure was specified by molecules, which and their neighbors up to the second hydration shell all have four H-bond coordinators. These molecules are referred as low-density liquid (LDL) and the others as high-density liquid (HDL). The water dynamics relaxation was studied through the self-intermediate scattering function, the non-Gaussian parameter, and the polarizability anisotropy time correlation function. Indicated by our simulations, the temperature dependence of the stretched exponent describing the α-relaxation displayed a small peak in the supercooled regime above the Widom line (WL), where LDL at the peak temperature was roughly one fourth of the total. The stretched exponent depicting the polarizability anisotropy relaxation was found to be insensitive to temperature, consistent with the experimental results. Above the WL, all relaxation times studied displayed a power-law temperature dependence with a consistent singular temperature for each model. The inverse relaxation times showed exponential functions of two-body excess entropy due to translational motions, where the entropy exhibited a logarithmic temperature behavior with a singular temperature close to that of relaxation time. This result leads to a conclusion that excess entropy is a quantity to describe dynamic relaxation of supercooled water in the thermodynamic region where the mode-coupling theory works. The water structure that causes the two-body excess entropy is illustrated and the contributions of HDL, LDL, and their mixing are also shown, where the mixing contributes significantly as near the WL. Below the WL, the formula based on the two-body excess entropy may no longer be valid.
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DOI：
10.1073/pnas.2018379118
发表时间：
2021-02-09
影响因子：
11.1
作者：
Pathak H;Späh A;Esmaeildoost N;Sellberg JA;Kim KH;Perakis F;Amann-Winkel K;Ladd-Parada M;Koliyadu J;Lane TJ;Yang C;Lemke HT;Oggenfuss AR;Johnson PJM;Deng Y;Zerdane S;Mankowsky R;Beaud P;Nilsson A
通讯作者：
Nilsson A
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DOI：
10.1016/j.cpc.2010.07.014
发表时间：
2011
期刊：
Comput. Phys. Commun.
影响因子：
--
作者：
K. Tsai;Ten
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过冷水和动力学玻璃化转变。
DOI：
--
发表时间：
1996
期刊：
Physical review. E, Statistical physics, plasmas, fluids, and related interdisciplinary topics
影响因子：
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作者：
F. Sciortino;P. Gallo;P. Tartaglia;Sow
通讯作者：
Sow
影响因子：
1.7
作者：
Handle PH;Sciortino F
通讯作者：
Sciortino F
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DOI：
10.1063/1.5100811
发表时间：
2019
期刊：
The Journal of chemical physics
影响因子：
--
作者：
H. Pathak;Alexander Späh;Kyung Hwan Kim;Ifigeneia Tsironi;Daniel Mariedahl;M. Blanco;S. Huotari;V. Honkimäki;A. Nilsson
通讯作者：
A. Nilsson