# Difference between revisions of "SPC/E model of water"

Carl McBride (talk | contribs) m (Added parameters + a new reference) |
Carl McBride (talk | contribs) m (Added magnitude symbols to the H charge (thanks to Jeffcomer)) |
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{{Stub-water}} | {{Stub-water}} | ||

− | The extended simple point charge model, ''' | + | 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 | 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: | ||

− | [[Image: | + | [[Image:Thee_site_water_model.png|center|400px]] |

{| border="1" | {| border="1" | ||

|- | |- | ||

| parameter || value | | parameter || value | ||

|- | |- | ||

− | | <math>\sigma</math> || <math> 3.166 | + | | <math>\sigma</math> || <math> 3.166 </math> Å |

|- | |- | ||

| <math>\epsilon</math> || <math>0.650</math> kJ mol<sup>-1</sup> | | <math>\epsilon</math> || <math>0.650</math> kJ mol<sup>-1</sup> | ||

|- | |- | ||

− | | <math>r_\mathrm{OH}</math> || <math>1.000 | + | | <math>r_\mathrm{OH}</math> || <math>1.000</math> Å |

|- | |- | ||

| <math>\angle_\mathrm{HOH}</math> || <math>109.47^{\circ}</math> | | <math>\angle_\mathrm{HOH}</math> || <math>109.47^{\circ}</math> | ||

Line 18: | Line 19: | ||

| <math>q_{\mathrm{O}}</math> || <math>-0.8476 e</math> | | <math>q_{\mathrm{O}}</math> || <math>-0.8476 e</math> | ||

|- | |- | ||

− | | <math>q_{\mathrm{H}}</math> || <math>q_{\mathrm{O}}/2</math> (charge neutrality | + | | <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), | + | 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> | ||

+ | ==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== | ||

− | + | <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: water]] | ||

[[category: models]] | [[category: models]] |

## Latest revision as of 14:30, 4 February 2015

The **SPC/E** (extended simple point charge model) ^{[1]}
^{[2]} is a slight reparameterisation of the SPC model of water, with a modified value for .
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 |

Å | |

kJ mol^{-1}
| |

Å | |

(charge neutrality) |

The SPC/E model has a dipole moment of 2.351 D. (Ref. 1 Table I).

## Contents

## Surface tension[edit]

The surface tension has been studied for the SPC/E model by Vega and Miguel
^{[3]}

## Phase diagram[edit]

### Plastic crystal phases[edit]

Recent simulations have demonstrated the existence of plastic crystal phases for the SPC/E model.
^{[4]}

## Shear viscosity[edit]

The shear viscosity for the SPC/E model is 0.729 mPa.s at 298 K and 1 bar ^{[5]} (experimental value 0.896 mPa.s ^{[6]}).

## Thermal conductivity[edit]

Thermal conductivity ^{[7]}.

## References[edit]

- ↑ 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) - ↑ 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) - ↑ 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) - ↑ J. L. Aragones and C. Vega "Plastic crystal phases of simple water models", Journal of Chemical Physics
**130**244504 (2009) - ↑ Miguel Angel González and José L. F. Abascal "The shear viscosity of rigid water models", Journal of Chemical Physics
**132**096101 (2010) - ↑ 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) - ↑ 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)

- Related reading