A potential model intended to be a general purpose model for the condensed phases of water is presented. TIP4P/2005 is a rigid four site model which consists of three fixed point charges and one Lennard-Jones center. The parametrization has been based on a fit of the temperature of maximum density (indirectly estimated from the melting point of hexagonal ice), the stability of several ice polymorphs and other commonly used target quantities. The calculated properties include a variety of thermodynamic properties of the liquid and solid phases, the phase diagram involving condensed phases, properties at melting and vaporization, dielectric constant, pair distribution function, and self-diffusion coefficient. These properties cover a temperature range from 123to573K and pressures up to 40000bar. The model gives an impressive performance for this variety of properties and thermodynamic conditions. For example, it gives excellent predictions for the densities at 1bar with a maximum density at 278K and an aver...

http://cacharro.quim.ucm.es/publicaciones/JCP_123_234505_2005.pdf

A general purpose model for the condensed phases of water: TIP4P/2005

A new classical empirical potential is proposed for water. The model uses a polarizable atomic multipole description of electrostatic interactions. Multipoles through the quadrupole are assigned to each atomic center based on a distributed multipole analysis (DMA) derived from large basis set molecular orbital calculations on the water monomer. Polarization is treated via self-consistent induced atomic dipoles. A modified version of Thole's interaction model is used to damp induction at short range. Repulsion−dispersion (vdW) effects are computed from a buffered 14−7 potential. In a departure from most current water potentials, we find that significant vdW parameters are necessary on hydrogen as well as oxygen. The new potential is fully flexible and has been tested versus a variety of experimental data and quantum calculations for small clusters, liquid water, and ice. Overall, excellent agreement with experimental and high level ab initio results is obtained for numerous properties, including cluster st...

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Polarizable Atomic Multipole Water Model for Molecular Mechanics Simulation

The unique properties of water in the supercooled (metastable) state are not fully understood. In particular, the effects of solutes and mechanical pressure on the kinetics of the liquid-to-solid phase transition of supercooled water and aqueous solutions to ice have remained unresolved. Here we show from experimental data that the homogeneous nucleation of ice from supercooled aqueous solutions is independent of the nature of the solute, but depends only on the water activity of the solution--that is, the ratio between the water vapour pressures of the solution and of pure water under the same conditions. In addition, we show that the presence of solutes and the application of pressure have a very similar effect on ice nucleation. We present a thermodynamic theory for homogeneous ice nucleation, which expresses the nucleation rate coefficient as a function of water activity and pressure. Recent observations from clouds containing ice are in good agreement with our theory and our results should help to overcome one of the main weaknesses of numerical models of the atmosphere, the formulation of cloud processes.

Water activity as the determinant for homogeneous ice nucleation in aqueous solutions

The anomalous properties of cold and supercooled water, such as the fact that at sufficiently low temperatures it becomes more compressible and less dense when cooled, and more fluid when compressed, have attracted the attention of physical scientists for a long time. The discovery in the 1970s that several thermodynamic and transport properties of supercooled water exhibit a pronounced temperature dependence and appear to diverge slightly below the homogeneous nucleation temperature inspired a large number of experimental and theoretical studies. Likewise, an important body of work on glassy water has been stimulated by experiments, starting in the mid-1980s and continuing to this date, which suggest that vitreous water can exist in at least two apparently distinct forms. A coherent theory of the thermodynamic and transport properties of supercooled and glassy water does not yet exist. Nevertheless, significant progress towards this goal has been made during the past 20 years. This article summarizes the known experimental facts and reviews critically theoretical and computational work aimed at interpreting the observations and providing a unified viewpoint on cold, non-crystalline, metastable states of water.

https://iopscience.iop.org/article/10.1088/0953-8984/15/45/R01/pdf

Supercooled and glassy water

The ability of several water models to predict the properties of ices is discussed. The emphasis is put on the results for the densities and the coexistence curves between the different ice forms. It is concluded that none of the most commonly used rigid models is satisfactory. A new model specifically designed to cope with solid-phase properties is proposed. The parameters have been obtained by fitting the equation of state and selected points of the melting lines and of the coexistence lines involving different ice forms. The phase diagram is then calculated for the new potential. The predicted melting temperature of hexagonal ice (Ih) at 1 bar is 272.2 K. This excellent value does not imply a deterioration of the rest of the properties. In fact, the predictions for both the densities and the coexistence curves are better than for TIP4P, which previously yielded the best estimations of the ice properties.

/pdf/a-potential-model-for-the-study-of-ices-and-amorphous-water-2dl9vf4x61.pdf

A potential model for the study of ices and amorphous water: TIP4P/Ice.

1. Introduction 1.1 The importance of ice 1.2 The physics of ice and structure of the book 1.3 The water molecule 1.4 The hydrogen bond 2. Ice Ih 2.1 Introduction 2.2 Crystal structure 2.3 Zero-point entropy 2.4 Lattice energy and hydrogen bonding 2.5 The actual structure 2.6 Summary 3. Elastic, thermal, and lattice dynamical properties 3.1 Introduction 3.2 Elasticity 3.3 Thermal properties 3.4 Spectroscopy of lattice vibrations 3.5 Modelling 4. Electrical properties-theory 4.1 Basics 4.2 Frequency dependence of the Debye relaxation 4.3 The static susceptibility ?s 4.4 Protonic point defects 4.5 Jaccard theory 4.6 Ice with blocking electrodes 4.7 Time constraints 4.8 Summary 5. Electrical properties-experimental 5.1 Introduction 5.2 Techniques 5.3 Pure ice 5.4 Doped ice 5.5 Charge exchange at ice-metal electrodes 5.6 Space-change effects 5.7 Injection and extraction of charge carriers 5.8 Thermally-stimulated depolarization 6. Point defects 6.1 Introduction 6.2 Thermal equilibrium concentrations 6.3 Diffusion and mobility 6.4 Molecular defects 6.5 Protonic point defects 6.6 Nuclear magnetic resonance 6.7 Muon spin rotation, relaxation, and resonance 6.8 Chemical impurities 6.9 Electronic defects 6.10 Photoconductivity 6.11 Review 7. Dislocations and planar defects 7.1 Introduction to dislocations 7.2 Dislocations in the ice structure 7.3 Direct observation of dislocations 7.4 Dislocation mobility 7.5 Electrical effects 7.6 Stacking faults 7.7 Grain boundaries 8. Mechanical properties 8.1 Introduction 8.2 Plastic deformation of single crystals 8.3 Plastic deformation of polycrystalline ice 8.4 Brittle fracture of polycrystalline ice 8.5 Summary 9. Optical and electronic properties 9.1 Introduction 9.2 Propagation of electromagnetic waves in ice 9.3 Infrared range 9.4 Visible optical range-birefringence 9.5 Ultraviolet range 9.6 Electronic structure 10. The surface of ice 10.1 Introduction 10.2 Surface structure 10.3 Optical ellipsometry and microscopy 10.4 Electrical properties of the surface 10.5 Nuclear magnetic resonance 10.6 Scanning force microscopy 10.7 Surface energy 10.8 Review of experimental evidence 10.9 Theoretical models 10.10 Conclusions 11. The other phases of ice 11.1 Introduction 11.2 Ice XI-the ordered form of ice Ih 11.3 Ices VII and VIII 11.4 Ice VI 11.5 Ice II 11.6 Ices III, IV, V, IX, and XII 11.7 Ice X and beyond 11.8 Cubic ice (Ice Ic) 11.9 Amorphous ices 11.10 Clathrate hydrates 11.11 Lattice vibrations and the hydrogen bond 12. Ice in nature 12.1 Lake and river ice 12.2 Sea ice 12.3 Ice in the atmosphere 12.4 Snow 12.5 Glacier and polar ice 12.6 Frozen ground 12.7 Ice in the Solar System 13. Adhesion and friction 13.1 Experiments on adhesion 13.2 Physical mechanisms of adhesion 13.3 Friction

Physics of Ice

Optical and electronic properties

: This report examines point defects in ice: molecular defects (vacancies and interstitials), protonic point defects (ions and Bjerrum defects) and electronic point defects (solvated electrons and radicals). Experimental results and theoretical models of the defects' atomic and electronic structures, energies and mobilities are reviewed. Special attention is given to the results of studies from the last two decades. Among the experimental techniques under consideration are nuclear magnetic resonance, X-rays topography, electron spin resonance, measurements of ice conductivity and dielectric permittivity, spectra of optical absorption and photoluminescence and measurements of diffusion coefficients of the oxygen and hydrogen isotopes in ice. Ab initio calculations, computer simulations, Jaccard's theory and soliton models are used to discuss the defects' structures and their properties. Ice, Molecular structure, Ice physics, Point defects.

Victor F. Petrenko

Papers

Physics of Ice

Optical and electronic properties

Structure of Ordinary Ice IH. Part 2: Defects in Ice Volume 1: Point Defects

The other phases of ice

Elastic, thermal, and lattice dynamical properties