skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: A comprehensive scenario of the thermodynamic anomalies of water using the TIP4P/2005 model

Abstract

The striking behavior of water has deserved it to be referred to as an “anomalous” liquid. The water anomalies are greatly amplified in metastable (supercooled and/or stretched) regions. This makes difficult a complete experimental description since, beyond certain limits, the metastable phase necessarily transforms into the stable one. Theoretical interpretation of the water anomalies could then be based on simulation results of well validated water models. But the analysis of the simulations has not yet reached a consensus. In particular, one of the most popular theoretical scenarios—involving the existence of a liquid-liquid critical point (LLCP)—is disputed by several authors. In this work, we propose to use a number of exact thermodynamic relations which may shed light on this issue. Interestingly, these relations may be tested in a region of the phase diagram which is outside the LLCP thus avoiding the problems associated to the coexistence region. The central property connected to other water anomalies is the locus of temperatures at which the density along isobars attain a maximum (TMD line) or a minimum (TmD). We have performed computer simulations to evaluate the TMD and TmD for a successful water model, namely, TIP4P/2005. We have also evaluated the vapor-liquid (VL) spinodalmore » in the region of large negative pressures. The shape of these curves and their connection to the extrema of some response functions, in particular the isothermal compressibility and heat capacity at constant pressure, provides very useful information which may help to elucidate the validity of the theoretical proposals. In this way, we are able to present for the first time a comprehensive scenario of the thermodynamic water anomalies for TIP4P/2005 and their relation to the vapor-liquid spinodal. The overall picture shows a remarkable similarity with the corresponding one for the ST2 water model, for which the existence of a LLCP has been demonstrated in recent years. It also provides a hint as to where the long-sought for extrema in response functions might become accessible to experiments.« less

Authors:
 [1];  [2];  [1];  [3];  [4];  [1]
  1. Departamento Química Física I, Facultad Ciencias Químicas, Universidad Complutense de Madrid, 28040 Madrid (Spain)
  2. (United Kingdom)
  3. (Spain)
  4. Institut Lumière Matière, UMR5306 Université Claude Bernard Lyon 1-CNRS, Université de Lyon, 69622 Villeurbanne Cedex (France)
Publication Date:
OSTI Identifier:
22679030
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Chemical Physics; Journal Volume: 145; Journal Issue: 5; Other Information: (c) 2016 Author(s); Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
37 INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY; COMPUTERIZED SIMULATION; EXPERIMENTAL DATA; PHASE DIAGRAMS; RESPONSE FUNCTIONS; SPECIFIC HEAT; THERMODYNAMICS

Citation Formats

González, Miguel A., Department of Chemistry, Imperial College London, London SW7 2AZ, Valeriani, Chantal, Departamento Física Aplicada I, Facultad Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Caupin, Frédéric, and Abascal, José L. F. A comprehensive scenario of the thermodynamic anomalies of water using the TIP4P/2005 model. United States: N. p., 2016. Web. doi:10.1063/1.4960185.
González, Miguel A., Department of Chemistry, Imperial College London, London SW7 2AZ, Valeriani, Chantal, Departamento Física Aplicada I, Facultad Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Caupin, Frédéric, & Abascal, José L. F. A comprehensive scenario of the thermodynamic anomalies of water using the TIP4P/2005 model. United States. doi:10.1063/1.4960185.
González, Miguel A., Department of Chemistry, Imperial College London, London SW7 2AZ, Valeriani, Chantal, Departamento Física Aplicada I, Facultad Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid, Caupin, Frédéric, and Abascal, José L. F. Sun . "A comprehensive scenario of the thermodynamic anomalies of water using the TIP4P/2005 model". United States. doi:10.1063/1.4960185.
@article{osti_22679030,
title = {A comprehensive scenario of the thermodynamic anomalies of water using the TIP4P/2005 model},
author = {González, Miguel A. and Department of Chemistry, Imperial College London, London SW7 2AZ and Valeriani, Chantal and Departamento Física Aplicada I, Facultad Ciencias Físicas, Universidad Complutense de Madrid, 28040 Madrid and Caupin, Frédéric and Abascal, José L. F.},
abstractNote = {The striking behavior of water has deserved it to be referred to as an “anomalous” liquid. The water anomalies are greatly amplified in metastable (supercooled and/or stretched) regions. This makes difficult a complete experimental description since, beyond certain limits, the metastable phase necessarily transforms into the stable one. Theoretical interpretation of the water anomalies could then be based on simulation results of well validated water models. But the analysis of the simulations has not yet reached a consensus. In particular, one of the most popular theoretical scenarios—involving the existence of a liquid-liquid critical point (LLCP)—is disputed by several authors. In this work, we propose to use a number of exact thermodynamic relations which may shed light on this issue. Interestingly, these relations may be tested in a region of the phase diagram which is outside the LLCP thus avoiding the problems associated to the coexistence region. The central property connected to other water anomalies is the locus of temperatures at which the density along isobars attain a maximum (TMD line) or a minimum (TmD). We have performed computer simulations to evaluate the TMD and TmD for a successful water model, namely, TIP4P/2005. We have also evaluated the vapor-liquid (VL) spinodal in the region of large negative pressures. The shape of these curves and their connection to the extrema of some response functions, in particular the isothermal compressibility and heat capacity at constant pressure, provides very useful information which may help to elucidate the validity of the theoretical proposals. In this way, we are able to present for the first time a comprehensive scenario of the thermodynamic water anomalies for TIP4P/2005 and their relation to the vapor-liquid spinodal. The overall picture shows a remarkable similarity with the corresponding one for the ST2 water model, for which the existence of a LLCP has been demonstrated in recent years. It also provides a hint as to where the long-sought for extrema in response functions might become accessible to experiments.},
doi = {10.1063/1.4960185},
journal = {Journal of Chemical Physics},
number = 5,
volume = 145,
place = {United States},
year = {Sun Aug 07 00:00:00 EDT 2016},
month = {Sun Aug 07 00:00:00 EDT 2016}
}
  • Water shows intriguing thermodynamic and dynamic anomalies in the supercooled liquid state. One possible explanation of the origin of these anomalies lies in the existence of a metastable liquid-liquid phase transition (LLPT) between two (high and low density) forms of water. While the anomalies are observed in experiments on bulk and confined water and by computer simulation studies of different water-like models, the existence of a LLPT in water is still debated. Unambiguous experimental proof of the existence of a LLPT in bulk supercooled water is hampered by fast ice nucleation which is a precursor of the hypothesized LLPT. Moreover,more » the hypothesized LLPT, being metastable, in principle cannot exist in the thermodynamic limit (infinite size, infinite time). Therefore, computer simulations of water models are crucial for exploring the possibility of the metastable LLPT and the nature of the anomalies. In this work, we present new simulation results in the NVT ensemble for one of the most accurate classical molecular models of water, TIP4P/2005. To describe the computed properties and explore the possibility of a LLPT, we have applied two-structure thermodynamics, viewing water as a non-ideal mixture of two interconvertible local structures (“states”). The results suggest the presence of a liquid-liquid critical point and are consistent with the existence of a LLPT in this model for the simulated length and time scales. We have compared the behavior of TIP4P/2005 with other popular water-like models, namely, mW and ST2, and with real water, all of which are well described by two-state thermodynamics. In view of the current debate involving different studies of TIP4P/2005, we discuss consequences of metastability and finite size in observing the liquid-liquid separation. We also address the relationship between the phenomenological order parameter of two-structure thermodynamics and the microscopic nature of the low-density structure.« less
  • We perform extensive Gibbs Ensemble Monte Carlo simulations to study the capability of some recently re-parameterizations of the original TIP4P model intended to predict accurately the vapor-liquid coexistence envelope of water, its critical point, and its temperature dependence for the vapor pressure and second virial coefficient, and complement this analysis with the characterization of some specific crystalline faces of ice. We also disclose some trends between the resulting dipole moment of the models and the Lennard-Jones parameters, the location of the negative charge, as well as the estimated critical temperature. Finally, we discuss the inability of these models to predictmore » accurately and simultaneously the melting temperature and the temperature of maximum density.« less
  • We perform molecular dynamics simulations to observe the structure and dynamics of water using different water models (TIP3P, TIP4P, TIP5P) at ambient conditions, constrained by planar walls, which are either modeled by smooth potentials or regular atomic lattices, imitating the honeycomb-structure of graphene. We implement walls of different hydroaffinity, different lattice constant, and different types of interaction with the water molecules. We find that in the hydrophobic regime the smooth wall generally represents a good abstraction of the atomically rough walls, while in the hydrophilic regime there are noticeable differences in structure and dynamics between all stages of wall roughness.more » For a small lattice constant however the smooth and the atomically rough wall still share a number of structural and dynamical similarities. Out of the three water models, TIP5P water shows the largest degree of tetrahedral ordering and is often the one that is least perturbed by the presence of the wall.« less
  • Monovalent ions such as alkalis and halides play essential roles in aqueous and biological systems; thus a proper representation of these ions is significant in explicit molecular dynamics simulations. In this study, we re-parameterize ions interaction potentials based on TIP4PEw water at 298K with the additive non-polarizable models. The charges of the ions were kept as +1 for alkali metal ions (Li+, Na+, K+, Rb+, Cs+) and -1 for halides (F-, Cl-, Br-, I-). The experimental enthalpies of hydration were used to optimize the potential parameters. To validate the potential models, extensive molecular dynamics calculations were carried out to examinemore » the bulk, interfacial, static structural and dynamical properties of the aqueous ionic solutions. These included radial distribution functions, angle distributions, velocity autocorrelation functions, diffusion coefficients, binding energies, mean residence time, surface potential, and potential of mean force. The computed results agreed with the experimental data and observations. LXD was funded by the Division of Chemical Sciences, Geosciences and Biosciences, Office of Basic Energy Sciences, US Department of Energy. Battelle operates the Pacific Northwest National Laboratory for the U.S. Department of Energy.« less
  • While the majority of fluids contract upon cooling, water expands when cooled below T = 4 deg. C at atmospheric pressure. This effect is called density anomaly. Besides the density anomaly, there are more than 60 other anomalies known for water. Diffusivity is one of them. For normal liquids the diffusion coefficient decreases under compression. However, experimental results have shown that for water at temperatures below approximately 10 deg. C, the diffusion coefficient increases under compression and has a maximum. The temperature of maximum density line, inside which the density anomaly occurs, and the line of maximum in diffusivity aremore » located in the same region of the pressure-temperature phase diagram of water. We show how simulations for water also show thermodynamic and dynamic anomalies. These anomalies are then demonstrated to be related to two length scales effective potential.« less