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SPC/E model of water

2023-11-23T15:10:55Z

Oliveirajs:

{{Stub-water}}
The '''SPC/E''' (extended simple point charge model) <ref>[http://dx.doi.org/10.1021/j100308a038 H. J. C. Berendsen, J. R. Grigera, and T. P. Straatsma "The missing term in effective pair potentials", Journal of Physical Chemistry '''91''' pp. 6269 - 6271 (1987)]</ref>
<ref>[http://dx.doi.org/10.1063/1.2841127 Swaroop Chatterjee, Pablo G. Debenedetti, Frank H. Stillinger, and Ruth M. Lynden-Bell "A computational investigation of thermodynamics, structure, dynamics and solvation behavior in modified water models", Journal of Chemical Physics '''128''' 124511 (2008)]</ref> is a slight reparameterisation of the [[SPC]] model of [[water]], with a modified value for <math>q_{\mathrm{O}}</math>.
The molecule is modelled as
a rigid isosceles triangle, having charges situated on each of the three atoms. Apart from Coulombic interactions, the molecules interact via long-range [[Lennard-Jones model | Lennard-Jones]] sites, situated on the oxygen atoms. The parameters are as follows:
[[Image:Thee_site_water_model.png‎|center|400px]]
{| border="1"
|-
| parameter || value
|-
| <math>\sigma</math> || <math> 3.166 </math> Å
|-
| <math>\epsilon</math> || <math>0.650</math> kJ mol<sup>-1</sup>
|-
| <math>r_\mathrm{OH}</math> || <math>1.000</math> Å
|-
| <math>\angle_\mathrm{HOH}</math> || <math>109.47^{\circ}</math>
|-
| <math>q_{\mathrm{O}}</math> || <math>-0.8476 e</math>
|-
| <math>q_{\mathrm{H}}</math> || <math>|q_{\mathrm{O}}|/2</math> (charge neutrality)
|}
The SPC/E model has a [[dipole moment]] of 2.351 D. (Ref. 1 Table I).
==Surface tension==
The [[surface tension]] has been studied for the SPC/E model by Vega and Miguel
<ref>[http://dx.doi.org/10.1063/1.2715577 C. Vega and E. de Miguel "Surface tension of the most popular models of water by using the test-area simulation method", Journal of Chemical Physics '''126''' 154707 (2007)]</ref>
==Phase diagram==
[[Image:SPC_E_phase_diagram.png|right|400px]]
===Plastic crystal phases===
Recent simulations have demonstrated the existence of [[Plastic crystals | plastic crystal]] phases for the SPC/E model.
<ref>[http://dx.doi.org/10.1063/1.3156856 J. L. Aragones and C. Vega "Plastic crystal phases of simple water models", Journal of Chemical Physics '''130''' 244504 (2009)]</ref>
<ref>[https://doi.org/10.1021/acs.jpcb.1c05053 I. Skarmoutsos, A. Henao, J. Samios and E. Guardia "On the Different Faces of the Supercritical Phase of Water at a Near-Critical Temperature: Pressure-Induced Structural Transitions Ranging from a Gaslike Fluid to a Plastic Crystal Polymorph", Journal of Physical Chemistry B '''125''' 10260 (2022)]</ref>
==Shear viscosity==
The [[shear viscosity]] for the SPC/E model is 0.729 mPa.s at 298 K and 1 bar <ref>[http://dx.doi.org/10.1063/1.3330544 Miguel Angel González and José L. F. Abascal "The shear viscosity of rigid water models", Journal of Chemical Physics '''132''' 096101 (2010)]</ref> (experimental value 0.896 mPa.s <ref>[http://dx.doi.org/10.1021/je049918m Kenneth R. Harris and Lawrence A. Woolf "Temperature and Volume Dependence of the Viscosity of Water and Heavy Water at Low Temperatures", Journal of Chemical & Engineering Data '''49''' pp. 1064-1069 (2004)]</ref>).

==Thermal conductivity==
[[Thermal conductivity]] <ref>[http://dx.doi.org/10.1063/1.4739855 Frank Römer, Anders Lervik, and Fernando Bresme "Nonequilibrium molecular dynamics simulations of the thermal conductivity of water: A systematic investigation of the SPC/E and TIP4P/2005 models", Journal of Chemical Physics '''137''' 074503 (2012)]</ref>.

==References==
<references/>
;Related reading
*[http://dx.doi.org/10.1063/1.3548869 Péter T. Kiss and András Baranyai "Sources of the deficiencies in the popular SPC/E and TIP3P models of water", Journal of Chemical Physics '''134''' 054106 (2011)]
[[category: water]]
[[category: models]]

SPC/E model of water

2023-11-23T15:10:19Z

Oliveirajs:

{{Stub-water}}
The '''SPC/E''' (extended simple point charge model) <ref>[http://dx.doi.org/10.1021/j100308a038 H. J. C. Berendsen, J. R. Grigera, and T. P. Straatsma "The missing term in effective pair potentials", Journal of Physical Chemistry '''91''' pp. 6269 - 6271 (1987)]</ref>
<ref>[http://dx.doi.org/10.1063/1.2841127 Swaroop Chatterjee, Pablo G. Debenedetti, Frank H. Stillinger, and Ruth M. Lynden-Bell "A computational investigation of thermodynamics, structure, dynamics and solvation behavior in modified water models", Journal of Chemical Physics '''128''' 124511 (2008)]</ref> is a slight reparameterisation of the [[SPC]] model of [[water]], with a modified value for <math>q_{\mathrm{O}}</math>.
The molecule is modelled as
a rigid isosceles triangle, having charges situated on each of the three atoms. Apart from Coulombic interactions, the molecules interact via long-range [[Lennard-Jones model | Lennard-Jones]] sites, situated on the oxygen atoms. The parameters are as follows:
[[Image:Thee_site_water_model.png‎|center|400px]]
{| border="1"
|-
| parameter || value
|-
| <math>\sigma</math> || <math> 3.166 </math> Å
|-
| <math>\epsilon</math> || <math>0.650</math> kJ mol<sup>-1</sup>
|-
| <math>r_\mathrm{OH}</math> || <math>1.000</math> Å
|-
| <math>\angle_\mathrm{HOH}</math> || <math>109.47^{\circ}</math>
|-
| <math>q_{\mathrm{O}}</math> || <math>-0.8476 e</math>
|-
| <math>q_{\mathrm{H}}</math> || <math>|q_{\mathrm{O}}|/2</math> (charge neutrality)
|}
The SPC/E model has a [[dipole moment]] of 2.351 D. (Ref. 1 Table I).
==Surface tension==
The [[surface tension]] has been studied for the SPC/E model by Vega and Miguel
<ref>[http://dx.doi.org/10.1063/1.2715577 C. Vega and E. de Miguel "Surface tension of the most popular models of water by using the test-area simulation method", Journal of Chemical Physics '''126''' 154707 (2007)]</ref>
==Phase diagram==
[[Image:SPC_E_phase_diagram.png|right|400px]]
===Plastic crystal phases===
Recent simulations have demonstrated the existence of [[Plastic crystals | plastic crystal]] phases for the SPC/E model.
<ref>[http://dx.doi.org/10.1063/1.3156856 J. L. Aragones and C. Vega "Plastic crystal phases of simple water models", Journal of Chemical Physics '''130''' 244504 (2009)]</ref>
<ref>[https://doi.org/10.1021/acs.jpcb.1c05053 I. Skarmoutsos, A. Henao, J.Samios and E. Guardia "On the Different Faces of the Supercritical Phase of Water at a Near-Critical Temperature: Pressure-Induced Structural Transitions Ranging from a Gaslike Fluid to a Plastic Crystal Polymorph", Journal of Physical Chemistry B '''125''' 10260 (2022)]</ref>
==Shear viscosity==
The [[shear viscosity]] for the SPC/E model is 0.729 mPa.s at 298 K and 1 bar <ref>[http://dx.doi.org/10.1063/1.3330544 Miguel Angel González and José L. F. Abascal "The shear viscosity of rigid water models", Journal of Chemical Physics '''132''' 096101 (2010)]</ref> (experimental value 0.896 mPa.s <ref>[http://dx.doi.org/10.1021/je049918m Kenneth R. Harris and Lawrence A. Woolf "Temperature and Volume Dependence of the Viscosity of Water and Heavy Water at Low Temperatures", Journal of Chemical & Engineering Data '''49''' pp. 1064-1069 (2004)]</ref>).

==Thermal conductivity==
[[Thermal conductivity]] <ref>[http://dx.doi.org/10.1063/1.4739855 Frank Römer, Anders Lervik, and Fernando Bresme "Nonequilibrium molecular dynamics simulations of the thermal conductivity of water: A systematic investigation of the SPC/E and TIP4P/2005 models", Journal of Chemical Physics '''137''' 074503 (2012)]</ref>.

==References==
<references/>
;Related reading
*[http://dx.doi.org/10.1063/1.3548869 Péter T. Kiss and András Baranyai "Sources of the deficiencies in the popular SPC/E and TIP3P models of water", Journal of Chemical Physics '''134''' 054106 (2011)]
[[category: water]]
[[category: models]]