Water point-charge models

Chelli R, Barducci A, Bellucci L, Schettino V, Procacci P (2005) Behavior of polarizable models in presence of strong electric fields. I. Origin of nonlinear effects in water point-charge systems. J Chem Phys 123(19) 194109... 

Svishchev IM, Kusalik PG, Wang J, Boyd RJ (1996) Polarizable point-charge model for water results under normal and extreme conditions. J Chem Phys 105(11) 4742 1750... 

A more sophisticated model for water molecule interactions is given by the four-point charge model. The interaction potential has the form... 

Figure 7.2 Bjerrum four point charge model for water.

In 1920, two men in G.N. Lewis laboratory at Berkeley proposed the hydrogen bond (Latimer and Rodebush, 1920) using a simplified electrostatic point charge model of the water molecule. The work by Kollman (1977) indicated that the simplified model remains acceptable because of a cancellation of two other energy components. 

O.A. Karim et al., The ice/water interface A molecular dynamics simulation using the simple point charge model. J. Chem. Phys. 92, 4634 1635 (1990)... 

Glattli A, Daura X, van Gunsteren WF (2003) A novel approach for designing simple point charge models for liquid water with three interaction sites, J Comput Chem, 24 1087-1096... 

Fig. 13 The change in calculated optical rotation of glycine as a function of inclusion of water molecules (QM or in form of a point-charge model) up to a cut-off distance from the solute. MD data to prepare plot taken from Kundrat and Autschbach [162]...

From = iv/(l - 8aecos0/a3) with pv = 1.86 D, we obtain tv = 2.138 D for the effective dipole moment in liquid water from the 298 K bulk dielectric constant. When this is used to estimate the cohesive energy between water molecules in approximately tetrahedral superdipoles at dipole-dipole or O O distances of 2.9 A, the results are about a factor of three too small. The simple dipole-dipole model for water was therefore replaced by a DP multipole-multipole point charge model for hydrogen bonding (c.f., Lih173), and the interactions... 

Calculations for two water molecules with their dipole axes and one lone pair each parallel (i.e., in parallel Verwey positions for positive ions, as would be possible in a Helmholtz double layer) in which an accurate DP point charge model was compared with a simple dipole model showed die latter to be 11.6% high at 2.0 A separation, and 4.6%, 1.5%, 0% high at 2.25, 2.5, and 2.75 A, and 1.4%, 2.6%, and 3.3% low at 3.0. 3.5. and 4.0 A. 

Polarizable Point-Charge Model for Water Results Under Normal and Extreme Conditions. 

Coexistence Properties for the Polarizable Point Charge Model of Water and the Effects of Applied Electric Field. 

The Effects of Pressure on Structural and Dynamical Properties of Associated Liquids Molecular Dynamics Calculations for the Extended Simple Point Charge Model of Water. 

For example, suppose one can choose a rigid three-point-charge model of water with an internal geometry of 109.47° and 100 pm for the HOH angle and OH distance, respectively. The interaction energy involves a Lennard-Jones 6-12 potential for electrostatic interactions between water-water and ion-water pairs, (/pair a nonadditive polarization energy, C/pg, and a term that includes exchange repulsion for ion-water and water-water pairs,... 

K. Bagchi, S. Balasubramanian, and M. L. Klein,/. Chem. Phys., 107, 8561 (1997). The Effects of Pressure on Structural and Dynamical Properties of Associated Liquids Molecular Dynamics Calculations for the Extended Simple Point Charge Model of Water. 

Figure 6. Hypothetical coupling of length scales in the attachment of two hydroxylated oxide nanoparticles in aqueous solution. The crystal cores are represented by continuum finite elements with elastic moduli Xy and dielectric tensor sy. The far-field continuum solvent has viscosity p, dielectric constant s, and exerts random boundary forces Fstoch on the fluid inside the large sphere modeled using particle methods. SPC is a simple point charge model for water.

Errington, J.R. and Panagiotopoulos, A.Z. (1998). A fixed point charge model for water optimized to the vapor-liquid coexistence properties. J. Phys. Chem. B, 102, 7470-5. 

Hummer G, Grdnbech-Jensen N, Neumann M. Pressure calculation in polar and charged systems using Ewald summation results for the extended simple point charge model of water. J. Chem. Phys. 1998 109 2791. 

Figure 23 Ab initio effective charge product (Eqs. [59] and [60]) in the D2/, water dimer (top). Filled squares, Qo,o, diamonds, Qo,Hj- The solid line is a least-squares fit to the O1O2 points. The coefficients of the curve are shown in the figure. The theoretical values for the intercept and slope, based on atomic multipoles of the water monomer, are 0.6194 and 1.341, demonstrating that the electrostatic properties of water dimers are described adequately by an atomic multipole model. Interestingly, the usual point-charge model would have predicted a line with zero slope (Reprinted with permission from ref. 120, copyright 1989 American Institute of Physics.)...

N. K. Ray, G. Bolis, M. Shibata, and R. Rein, hit. J. Quantum Chem., Quantum Biot. Symp., 11,257 (1984). Potential Derived Point Charge Model Study of Electrostatic Interaction Energies in Some Complexes of Water with Uracil, Thymine, and Cytosine. 

The field evolved out of the simulation of liquids and solutions and has adopted many of the models from there. Water, ions, and atoms are described by point charge models, augmented by empirical or ab initio short-range and dispersion potentials, the use of which has been validated for the bulk phase. Many models of the interface have been employed, ranging from representations of simple, atomically smooth walls to parametrized interaction potentials from ab initio quantum chemical calculations that describe the interactions with atomic crystals. The metallic character of the solid phase has in most cases been approximated by the image charge model. 

Shown in Fig. 21 are the quantum and classical solvent curves calculated for the same set of potential parameters. The water model was a flexible point-charge model, the specifics of which are described in... 

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