SPC/E model of water: Difference between revisions

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{{Stub-water}}
{{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>
The '''SPC/E''' (extended simple point charge model) UNIQ11bf423f66a234ea-ref-0000002B-QINU
<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>.
UNIQ11bf423f66a234ea-ref-0000002C-QINU is a slight reparameterisation  of the [[SPC]] model of [[water]], with a modified value for UNIQ11bf423f66a234ea-math-0000002D-QINU.
The molecule is modelled as
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:
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:
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| parameter || value
| parameter || value
|-   
|-   
| <math>\sigma</math> || <math> 3.166 </math> &Aring;  
| UNIQ11bf423f66a234ea-math-0000002E-QINU || UNIQ11bf423f66a234ea-math-0000002F-QINU &Aring;  
|-
|-
| <math>\epsilon</math> || <math>0.650</math> kJ mol<sup>-1</sup>
| UNIQ11bf423f66a234ea-math-00000030-QINU || UNIQ11bf423f66a234ea-math-00000031-QINU kJ mol<sup>-1</sup>
|-
|-
| <math>r_\mathrm{OH}</math> || <math>1.000</math> &Aring;
| UNIQ11bf423f66a234ea-math-00000032-QINU || UNIQ11bf423f66a234ea-math-00000033-QINU &Aring;
|-
|-
| <math>\angle_\mathrm{HOH}</math> || <math>109.47^{\circ}</math>
| UNIQ11bf423f66a234ea-math-00000034-QINU || UNIQ11bf423f66a234ea-math-00000035-QINU
|-
|-
| <math>q_{\mathrm{O}}</math> ||  <math>-0.8476 e</math>
| UNIQ11bf423f66a234ea-math-00000036-QINU ||  UNIQ11bf423f66a234ea-math-00000037-QINU
|-
|-
| <math>q_{\mathrm{H}}</math> ||  <math>q_{\mathrm{O}}/2</math> (charge neutrality)
| UNIQ11bf423f66a234ea-math-00000038-QINU ||  UNIQ11bf423f66a234ea-math-00000039-QINU (charge neutrality)
|}
|}
The SPC/E model has a [[dipole moment]] of 2.351 D. (Ref. 1 Table I).
The SPC/E model has a [[dipole moment]] of 2.351 D. (Ref. 1 Table I).
==Surface tension==
==Surface tension==
The [[surface tension]] has been studied for the SPC/E model by Vega and Miguel
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>
UNIQ11bf423f66a234ea-ref-0000003A-QINU
==Phase diagram==
==Phase diagram==
[[Image:SPC_E_phase_diagram.png|right|400px]]
[[Image:SPC_E_phase_diagram.png|right|400px]]
===Plastic crystal phases===
===Plastic crystal phases===
Recent simulations have demonstrated the existence of  [[Plastic crystals | plastic crystal]] phases for the SPC/E model.
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>
UNIQ11bf423f66a234ea-ref-0000003B-QINU
==Shear viscosity==
==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>).
The [[shear viscosity]] for the SPC/E model is 0.729 mPa.s at 298 K and 1 bar UNIQ11bf423f66a234ea-ref-0000003C-QINU (experimental value 0.896  mPa.s UNIQ11bf423f66a234ea-ref-0000003D-QINU).


==Thermal conductivity==
==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>.
[[Thermal conductivity]] UNIQ11bf423f66a234ea-ref-0000003E-QINU.


==References==
==References==
<references/>
UNIQ11bf423f66a234ea-references-0000003F-QINU
;Related reading
;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)]
*[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: water]]
[[category: models]]
[[category: models]]

Revision as of 17:04, 24 December 2014

This article is a 'stub' about water and/or ice. It has no, or next to no, content. It is here at the moment to help form part of the structure of SklogWiki. If you add material to this article, remove the {{Stub-water}} template from this page.

The SPC/E (extended simple point charge model) ?UNIQ11bf423f66a234ea-ref-0000002B-QINU? ?UNIQ11bf423f66a234ea-ref-0000002C-QINU? is a slight reparameterisation of the SPC model of water, with a modified value for ?UNIQ11bf423f66a234ea-math-0000002D-QINU?. 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 sites, situated on the oxygen atoms. The parameters are as follows:

parameter value
?UNIQ11bf423f66a234ea-math-0000002E-QINU? ?UNIQ11bf423f66a234ea-math-0000002F-QINU? Å
?UNIQ11bf423f66a234ea-math-00000030-QINU? ?UNIQ11bf423f66a234ea-math-00000031-QINU? kJ mol-1
?UNIQ11bf423f66a234ea-math-00000032-QINU? ?UNIQ11bf423f66a234ea-math-00000033-QINU? Å
?UNIQ11bf423f66a234ea-math-00000034-QINU? ?UNIQ11bf423f66a234ea-math-00000035-QINU?
?UNIQ11bf423f66a234ea-math-00000036-QINU? ?UNIQ11bf423f66a234ea-math-00000037-QINU?
?UNIQ11bf423f66a234ea-math-00000038-QINU? ?UNIQ11bf423f66a234ea-math-00000039-QINU? (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 ?UNIQ11bf423f66a234ea-ref-0000003A-QINU?

Phase diagram

Plastic crystal phases

Recent simulations have demonstrated the existence of plastic crystal phases for the SPC/E model. ?UNIQ11bf423f66a234ea-ref-0000003B-QINU?

Shear viscosity

The shear viscosity for the SPC/E model is 0.729 mPa.s at 298 K and 1 bar ?UNIQ11bf423f66a234ea-ref-0000003C-QINU? (experimental value 0.896 mPa.s ?UNIQ11bf423f66a234ea-ref-0000003D-QINU?).

Thermal conductivity

Thermal conductivity ?UNIQ11bf423f66a234ea-ref-0000003E-QINU?.

References

?UNIQ11bf423f66a234ea-references-0000003F-QINU?

Related reading
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