SPC/E model of water: Difference between revisions

From SklogWiki
Jump to navigation Jump to search
(Need minus sign for charge neutrality)
(Undo revision 14452 by Jeffcomer (talk))
Line 1: Line 1:
{{Stub-water}}
{{Stub-water}}
The '''SPC/E''' (extended simple point charge model) UNIQ11bf423f66a234ea-ref-0000002B-QINU
The '''SPC/E''' (extended simple point charge model) UNIQ07be08afbd145544-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.
UNIQ07be08afbd145544-ref-0000002C-QINU is a slight reparameterisation  of the [[SPC]] model of [[water]], with a modified value for UNIQ07be08afbd145544-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:
Line 9: Line 9:
| parameter || value
| parameter || value
|-   
|-   
| UNIQ11bf423f66a234ea-math-0000002E-QINU || UNIQ11bf423f66a234ea-math-0000002F-QINU Å  
| UNIQ07be08afbd145544-math-0000002E-QINU || UNIQ07be08afbd145544-math-0000002F-QINU Å  
|-
|-
| UNIQ11bf423f66a234ea-math-00000030-QINU || UNIQ11bf423f66a234ea-math-00000031-QINU kJ mol<sup>-1</sup>
| UNIQ07be08afbd145544-math-00000030-QINU || UNIQ07be08afbd145544-math-00000031-QINU kJ mol<sup>-1</sup>
|-
|-
| UNIQ11bf423f66a234ea-math-00000032-QINU || UNIQ11bf423f66a234ea-math-00000033-QINU &Aring;
| UNIQ07be08afbd145544-math-00000032-QINU || UNIQ07be08afbd145544-math-00000033-QINU &Aring;
|-
|-
| UNIQ11bf423f66a234ea-math-00000034-QINU || UNIQ11bf423f66a234ea-math-00000035-QINU
| UNIQ07be08afbd145544-math-00000034-QINU || UNIQ07be08afbd145544-math-00000035-QINU
|-
|-
| UNIQ11bf423f66a234ea-math-00000036-QINU ||  UNIQ11bf423f66a234ea-math-00000037-QINU
| UNIQ07be08afbd145544-math-00000036-QINU ||  UNIQ07be08afbd145544-math-00000037-QINU
|-
|-
| UNIQ11bf423f66a234ea-math-00000038-QINU ||  UNIQ11bf423f66a234ea-math-00000039-QINU (charge neutrality)
| UNIQ07be08afbd145544-math-00000038-QINU ||  UNIQ07be08afbd145544-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
UNIQ11bf423f66a234ea-ref-0000003A-QINU
UNIQ07be08afbd145544-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.
UNIQ11bf423f66a234ea-ref-0000003B-QINU
UNIQ07be08afbd145544-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 UNIQ11bf423f66a234ea-ref-0000003C-QINU (experimental value 0.896  mPa.s UNIQ11bf423f66a234ea-ref-0000003D-QINU).
The [[shear viscosity]] for the SPC/E model is 0.729 mPa.s at 298 K and 1 bar UNIQ07be08afbd145544-ref-0000003C-QINU (experimental value 0.896  mPa.s UNIQ07be08afbd145544-ref-0000003D-QINU).


==Thermal conductivity==
==Thermal conductivity==
[[Thermal conductivity]] UNIQ11bf423f66a234ea-ref-0000003E-QINU.
[[Thermal conductivity]] UNIQ07be08afbd145544-ref-0000003E-QINU.


==References==
==References==
UNIQ11bf423f66a234ea-references-0000003F-QINU
UNIQ07be08afbd145544-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 19:06, 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) ?UNIQ07be08afbd145544-ref-0000002B-QINU? ?UNIQ07be08afbd145544-ref-0000002C-QINU? is a slight reparameterisation of the SPC model of water, with a modified value for ?UNIQ07be08afbd145544-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
?UNIQ07be08afbd145544-math-0000002E-QINU? ?UNIQ07be08afbd145544-math-0000002F-QINU? Å
?UNIQ07be08afbd145544-math-00000030-QINU? ?UNIQ07be08afbd145544-math-00000031-QINU? kJ mol-1
?UNIQ07be08afbd145544-math-00000032-QINU? ?UNIQ07be08afbd145544-math-00000033-QINU? Å
?UNIQ07be08afbd145544-math-00000034-QINU? ?UNIQ07be08afbd145544-math-00000035-QINU?
?UNIQ07be08afbd145544-math-00000036-QINU? ?UNIQ07be08afbd145544-math-00000037-QINU?
?UNIQ07be08afbd145544-math-00000038-QINU? ?UNIQ07be08afbd145544-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 ?UNIQ07be08afbd145544-ref-0000003A-QINU?

Phase diagram

Plastic crystal phases

Recent simulations have demonstrated the existence of plastic crystal phases for the SPC/E model. ?UNIQ07be08afbd145544-ref-0000003B-QINU?

Shear viscosity

The shear viscosity for the SPC/E model is 0.729 mPa.s at 298 K and 1 bar ?UNIQ07be08afbd145544-ref-0000003C-QINU? (experimental value 0.896 mPa.s ?UNIQ07be08afbd145544-ref-0000003D-QINU?).

Thermal conductivity

Thermal conductivity ?UNIQ07be08afbd145544-ref-0000003E-QINU?.

References

?UNIQ07be08afbd145544-references-0000003F-QINU?

Related reading