Square shoulder + square well model: Difference between revisions

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where <math>\Phi_{12}(r)</math> is the [[intermolecular pair potential]], <math>\epsilon_1</math> and <math>\epsilon_2</math> are the well ''depths'', <math>r</math> is the distance between site 1 and site 2  where <math>r := |\mathbf{r}_1 - \mathbf{r}_2|</math>, &sigma; is the hard core diameter
where <math>\Phi_{12}(r)</math> is the [[intermolecular pair potential]], <math>\epsilon_1</math> and <math>\epsilon_2</math> are the well ''depths'', <math>r</math> is the distance between site 1 and site 2  where <math>r := |\mathbf{r}_1 - \mathbf{r}_2|</math>, &sigma; is the hard core diameter
and <math>\lambda_1,\lambda_2>1</math>
and <math>\lambda_1,\lambda_2>1</math>
==Critical points and liquid-liquid transition==
==Liquid-liquid transition==
For certain parameter sets the square shoulder + square well model has a  [[Polyamorphic systems | liquid-liquid transition]] along with a corresponding liquid-liquid [[Critical points | critical point]]
For certain parameter sets the square shoulder + square well model has a  [[Polyamorphic systems | liquid-liquid transition]] along with a corresponding liquid-liquid [[Critical points | critical point]]
<ref>[http://dx.doi.org/10.1088/0953-8984/11/50/308 Andreas Lang, Gerhard Kahl, Christos N Likos, Hartmut Löwen and Martin Watzlawek "Structure and thermodynamics of square-well and square-shoulder fluids", Journal of Physics: Condensed Matter '''11''' pp. 10143-10161  (1999)]</ref>
<ref>[http://dx.doi.org/10.1038/35055514 Giancarlo Franzese, Gianpietro Malescio, Anna Skibinsky, Sergey V. Buldyrev, and H. Eugene Stanley "Generic mechanism for generating a liquid-liquid phase transition", Nature '''409''' pp. 692-695 (2001)]</ref>
<ref>[http://dx.doi.org/10.1038/35055514 Giancarlo Franzese, Gianpietro Malescio, Anna Skibinsky, Sergey V. Buldyrev, and H. Eugene Stanley "Generic mechanism for generating a liquid-liquid phase transition", Nature '''409''' pp. 692-695 (2001)]</ref>
<ref>[http://dx.doi.org/10.1103/PhysRevE.66.051206 Giancarlo Franzese, Gianpietro Malescio, Anna Skibinsky, Sergey V. Buldyrev, and H. Eugene Stanley, "Metstable liquid-liquid phase transition in a single-component system with only one crystal phase and no density anomaly", Physical Review E '''66''' 051206 (2002)]</ref>
<ref>[http://dx.doi.org/10.1103/PhysRevE.66.051206 Giancarlo Franzese, Gianpietro Malescio, Anna Skibinsky, Sergey V. Buldyrev, and H. Eugene Stanley, "Metstable liquid-liquid phase transition in a single-component system with only one crystal phase and no density anomaly", Physical Review E '''66''' 051206 (2002)]</ref>
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<references/>
<references/>
;Related reading
;Related reading
*[http://dx.doi.org/10.1088/0953-8984/11/50/308 Andreas Lang, Gerhard Kahl, Christos N Likos, Hartmut Löwen and Martin Watzlawek "Structure and thermodynamics of square-well and square-shoulder fluids", Journal of Physics: Condensed Matter '''11''' pp. 10143-10161  (1999)]
*[http://dx.doi.org/10.1063/1.2970884 W. Rzysko, O. Pizio, A. Patrykiejew, and S. Sokolowski "Phase diagram of a square-shoulder, square-well fluid revisited", Journal of Chemical Physics '''129''' 124502 (2008)]
*[http://dx.doi.org/10.1063/1.2970884 W. Rzysko, O. Pizio, A. Patrykiejew, and S. Sokolowski "Phase diagram of a square-shoulder, square-well fluid revisited", Journal of Chemical Physics '''129''' 124502 (2008)]
*[http://dx.doi.org/10.1063/1.2982162 Shiqi Zhou, A. Lajovic, and A. Jamnik "Local structures of fluid with discrete spherical potential: Theory and grand canonical ensemble Monte Carlo simulation",  Journal of Chemical Physics '''129''' 124503 (2008)]
*[http://dx.doi.org/10.1063/1.2982162 Shiqi Zhou, A. Lajovic, and A. Jamnik "Local structures of fluid with discrete spherical potential: Theory and grand canonical ensemble Monte Carlo simulation",  Journal of Chemical Physics '''129''' 124503 (2008)]
[[Category: Models]]
[[Category: Models]]
[[category: Polyamorphic systems]]
[[category: Polyamorphic systems]]

Revision as of 15:24, 6 April 2011

The Square shoulder + square well model consists, as its name suggests, of a combination of the square shoulder model and the square well model. The model is given by

Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \Phi_{12}\left( r \right) = \left\{ \begin{array}{ccc} \infty & ; & r < \sigma \\ \epsilon_1 & ; &\sigma \le r < \lambda_1 \sigma \\ - \epsilon_2 & ; &\lambda_1\sigma \le r < \lambda_2 \sigma \\ 0 & ; & r \ge \lambda_2 \sigma \end{array} \right. }

where Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \Phi_{12}(r)} is the intermolecular pair potential, Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \epsilon_1} and Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \epsilon_2} are the well depths, Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle r} is the distance between site 1 and site 2 where Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle r := |\mathbf{r}_1 - \mathbf{r}_2|} , σ is the hard core diameter and Failed to parse (SVG (MathML can be enabled via browser plugin): Invalid response ("Math extension cannot connect to Restbase.") from server "https://wikimedia.org/api/rest_v1/":): {\displaystyle \lambda_1,\lambda_2>1}

Liquid-liquid transition

For certain parameter sets the square shoulder + square well model has a liquid-liquid transition along with a corresponding liquid-liquid critical point [1] [2] [3] [4].

References

Related reading