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Title: The interplay between dynamic heterogeneities and structure of bulk liquid water: A molecular dynamics simulation study

Abstract

In order to study the interplay between dynamical heterogeneities and structural properties of bulk liquid water in the temperature range 130–350 K, thus including the supercooled regime, we use the explicit trend of the distribution functions of some molecular properties, namely, the rotational relaxation constants, the atomic mean-square displacements, the relaxation of the cross correlation functions between the linear and squared displacements of H and O atoms of each molecule, the tetrahedral order parameter q and, finally, the number of nearest neighbors (NNs) and of hydrogen bonds (HBs) per molecule. Two different potentials are considered: TIP4P-Ew and a model developed in this laboratory for the study of nanoconfined water. The results are similar for the dynamical properties, but are markedly different for the structural characteristics. In particular, for temperatures higher than that of the dynamic crossover between “fragile” (at higher temperatures) and “strong” (at lower temperatures) liquid behaviors detected around 207 K, the rotational relaxation of supercooled water appears to be remarkably homogeneous. However, the structural parameters (number of NNs and of HBs, as well as q) do not show homogeneous distributions, and these distributions are different for the two water models. Another dynamic crossover between “fragile” (at lower temperatures)more » and “strong” (at higher temperatures) liquid behaviors, corresponding to the one found experimentally at T{sup ∗} ∼ 315 ± 5 K, was spotted at T{sup ∗} ∼ 283 K and T{sup ∗} ∼ 276 K for the TIP4P-Ew and the model developed in this laboratory, respectively. It was detected from the trend of Arrhenius plots of dynamic quantities and from the onset of a further heterogeneity in the rotational relaxation. To our best knowledge, it is the first time that this dynamical crossover is detected in computer simulations of bulk water. On the basis of the simulation results, the possible mechanisms of the two crossovers at molecular level are discussed.« less

Authors:
;  [1];  [2];  [1];  [1]
  1. Dipartimento di Chimica e Farmacia, Università degli studi di Sassari, Sassari (Italy)
  2. Grupo de Matemática y Física Computacionales, Universidad de las Ciencias Informáticas (UCI), Carretera a San Antonio de los Baños, Km 21/2, La Lisa, La Habana (Cuba)
Publication Date:
OSTI Identifier:
22490849
Resource Type:
Journal Article
Journal Name:
Journal of Chemical Physics
Additional Journal Information:
Journal Volume: 142; Journal Issue: 24; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); Journal ID: ISSN 0021-9606
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; 97 MATHEMATICAL METHODS AND COMPUTING; ATOMS; COMPUTERIZED SIMULATION; CORRELATION FUNCTIONS; DISTRIBUTION; DISTRIBUTION FUNCTIONS; HYDROGEN; LIQUIDS; MOLECULAR DYNAMICS METHOD; MOLECULES; ORDER PARAMETERS; POTENTIALS; RELAXATION; TEMPERATURE RANGE 0400-1000 K; WATER

Citation Formats

Demontis, Pierfranco, Suffritti, Giuseppe B., Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Gulín-González, Jorge, Masia, Marco, Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Istituto Officina dei Materiali del CNR, UOS SLACS, Via Vienna 2, 07100 Sassari, and Sant, Marco. The interplay between dynamic heterogeneities and structure of bulk liquid water: A molecular dynamics simulation study. United States: N. p., 2015. Web. doi:10.1063/1.4922930.
Demontis, Pierfranco, Suffritti, Giuseppe B., Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Gulín-González, Jorge, Masia, Marco, Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Istituto Officina dei Materiali del CNR, UOS SLACS, Via Vienna 2, 07100 Sassari, & Sant, Marco. The interplay between dynamic heterogeneities and structure of bulk liquid water: A molecular dynamics simulation study. United States. doi:10.1063/1.4922930.
Demontis, Pierfranco, Suffritti, Giuseppe B., Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Gulín-González, Jorge, Masia, Marco, Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali, Istituto Officina dei Materiali del CNR, UOS SLACS, Via Vienna 2, 07100 Sassari, and Sant, Marco. Sun . "The interplay between dynamic heterogeneities and structure of bulk liquid water: A molecular dynamics simulation study". United States. doi:10.1063/1.4922930.
@article{osti_22490849,
title = {The interplay between dynamic heterogeneities and structure of bulk liquid water: A molecular dynamics simulation study},
author = {Demontis, Pierfranco and Suffritti, Giuseppe B. and Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali and Gulín-González, Jorge and Masia, Marco and Consorzio Interuniversitario Nazionale per la Scienza e Tecnologia dei Materiali and Istituto Officina dei Materiali del CNR, UOS SLACS, Via Vienna 2, 07100 Sassari and Sant, Marco},
abstractNote = {In order to study the interplay between dynamical heterogeneities and structural properties of bulk liquid water in the temperature range 130–350 K, thus including the supercooled regime, we use the explicit trend of the distribution functions of some molecular properties, namely, the rotational relaxation constants, the atomic mean-square displacements, the relaxation of the cross correlation functions between the linear and squared displacements of H and O atoms of each molecule, the tetrahedral order parameter q and, finally, the number of nearest neighbors (NNs) and of hydrogen bonds (HBs) per molecule. Two different potentials are considered: TIP4P-Ew and a model developed in this laboratory for the study of nanoconfined water. The results are similar for the dynamical properties, but are markedly different for the structural characteristics. In particular, for temperatures higher than that of the dynamic crossover between “fragile” (at higher temperatures) and “strong” (at lower temperatures) liquid behaviors detected around 207 K, the rotational relaxation of supercooled water appears to be remarkably homogeneous. However, the structural parameters (number of NNs and of HBs, as well as q) do not show homogeneous distributions, and these distributions are different for the two water models. Another dynamic crossover between “fragile” (at lower temperatures) and “strong” (at higher temperatures) liquid behaviors, corresponding to the one found experimentally at T{sup ∗} ∼ 315 ± 5 K, was spotted at T{sup ∗} ∼ 283 K and T{sup ∗} ∼ 276 K for the TIP4P-Ew and the model developed in this laboratory, respectively. It was detected from the trend of Arrhenius plots of dynamic quantities and from the onset of a further heterogeneity in the rotational relaxation. To our best knowledge, it is the first time that this dynamical crossover is detected in computer simulations of bulk water. On the basis of the simulation results, the possible mechanisms of the two crossovers at molecular level are discussed.},
doi = {10.1063/1.4922930},
journal = {Journal of Chemical Physics},
issn = {0021-9606},
number = 24,
volume = 142,
place = {United States},
year = {2015},
month = {6}
}