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	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20617</id>
		<title>Kern and Frenkel patchy model</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20617"/>
		<updated>2023-09-21T00:41:05Z</updated>

		<summary type="html">&lt;p&gt;128.42.195.43: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;The &#039;&#039;&#039;Kern and Frenkel&#039;&#039;&#039; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.1569473 Norbert Kern and Daan Frenkel &amp;quot;Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction&amp;quot;, Journal of Chemical Physics 118, 9882 (2003)]&amp;lt;/ref&amp;gt; [[Patchy particles |patchy model]] published in 2003 is an amalgamation of the [[hard sphere model]] with&lt;br /&gt;
attractive [[Square well model | square well]] patches (HSSW). The model was originally developed by Bol (1982),&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1080/00268978200100461 W. Bol &amp;quot;Monte Carlo simulations of fluid systems of waterlike molecules&amp;quot;, Molecular Physics &#039;&#039;&#039;45&#039;&#039;&#039; pp. 605-616 (1982)]&amp;lt;/ref&amp;gt; and later Chapman (1988) &amp;lt;ref name=&amp;quot;Chapman&amp;quot;&amp;gt;[W.G. Chapman, Doctoral Thesis, Cornell University (1988)]&amp;lt;/ref&amp;gt; &amp;lt;ref&amp;gt;[G. Jackson, W.G. Chapman, K.E. Gubbins, Molecular Physics 65, 1-31 (1988)]&amp;lt;/ref&amp;gt; reinvented the model as the basis for numerous articles describing properties of associating particles from molecular simulation and theory. The computational advantage of Bol&#039;s model is that only a simple dot product is required to determine if a particle is in the bonding orientation. &lt;br /&gt;
 The potential has an angular aspect, given by (Eq. 1)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;\Phi_{ij}({\mathbf r}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j)  =\Phi_{ij}^{ \mathrm{HSSW}}({\mathbf r}_{ij}) \cdot f(\tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j) &amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
where the radial component is given by the square well model (Eq. 2)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\Phi_{ij}^{ \mathrm{HSSW}} \left({\mathbf r}_{ij} \right) = &lt;br /&gt;
\left\{ \begin{array}{ccc}&lt;br /&gt;
\infty &amp;amp; ; &amp;amp; r &amp;lt; \sigma \\&lt;br /&gt;
- \epsilon &amp;amp; ; &amp;amp;\sigma \le r &amp;lt; \lambda \sigma \\&lt;br /&gt;
0         &amp;amp; ; &amp;amp; r \ge \lambda \sigma \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
and the orientational component is given by (Eq. 3)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
f_{ij} \left(\hat{ {\mathbf r}}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j \right) = &lt;br /&gt;
\left\{ \begin{array}{clc}&lt;br /&gt;
1         &amp;amp; \mathrm{if}        &amp;amp; \left\{ \begin{array}{ccc}     &amp;amp;  (\hat{e}_\alpha\cdot\hat{r}_{ij} \geq \cos \delta) &amp;amp; \mathrm{for~some~patch~\alpha~on~}i  \\ &lt;br /&gt;
                                                            \mathrm{and} &amp;amp; (\hat{e}_\beta\cdot\hat{r}_{ji} \geq \cos \delta)  &amp;amp; \mathrm{for~some~patch~\beta~on~}j  \end{array} \right. \\&lt;br /&gt;
0         &amp;amp; \mathrm{otherwise} &amp;amp;  \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; is the solid angle of a patch (&amp;lt;math&amp;gt;\alpha, \beta, ...&amp;lt;/math&amp;gt;) whose axis is &amp;lt;math&amp;gt;\hat{e}&amp;lt;/math&amp;gt; (see Fig. 1 of Ref. 1), forming a conical segment.&lt;br /&gt;
==Multiple patches==&lt;br /&gt;
The &amp;quot;two-patch&amp;quot; and &amp;quot;four-patch&amp;quot; Bol (Chapman or Kern and Frenkel) model was extensively studied by Chapman and co-workers for bulk and interfacial systems using hard sphere and Lennard-Jones reference systems.  Later other groups, including Sciortino and co-workers, considered stronger association energies for the &amp;quot;two-patch&amp;quot; hard sphere reference &amp;lt;ref name=&amp;quot;bianchi&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.2730797  F. Sciortino, E. Bianchi, J. Douglas and P. Tartaglia &amp;quot;Self-assembly of patchy particles into polymer chains: A parameter-free comparison between Wertheim theory and Monte Carlo simulation&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;126&#039;&#039;&#039; 194903 (2007)]&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3415490 Achille Giacometti, Fred Lado, Julio Largo, Giorgio Pastore, and Francesco Sciortino &amp;quot;Effects of patch size and number within a simple model of patchy colloids&amp;quot;, Journal of Chemical Physics 132, 174110 (2010)]&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.4737930  José Maria Tavares, Lorenzo Rovigatti, and Francesco Sciortino &amp;quot;Quantitative description of the self-assembly of patchy particles into chains and rings&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;137&#039;&#039;&#039; 044901 (2012)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
==Four patches==&lt;br /&gt;
:&#039;&#039;Main article: [[Anisotropic particles with tetrahedral symmetry]]&#039;&#039;&lt;br /&gt;
&lt;br /&gt;
==Single-bond-per-patch-condition==&lt;br /&gt;
If the two parameters &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\lambda&amp;lt;/math&amp;gt; fullfil the condition&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\sin{\delta} \leq \dfrac{1}{2(1+\lambda\sigma)}&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
then the patch cannot be involved in more than one bond. Enforcing this condition makes it possible to compare the simulations results with [[Wertheim&#039;s first order thermodynamic perturbation theory (TPT1)| Wertheim theory]] &amp;lt;ref name=&amp;quot;Chapman&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;bianchi&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Hard ellipsoid model==&lt;br /&gt;
The [[hard ellipsoid model]] has also been used as the &#039;nucleus&#039; of the Kern and Frenkel patchy model &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.4969074  T. N. Carpency, J. D. Gunton and J. M. Rickman &amp;quot;Phase behavior of patchy spheroidal fluids&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 214904 (2016)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
==References==&lt;br /&gt;
&amp;lt;references/&amp;gt;&lt;br /&gt;
;Related reading&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.3689308 Christoph Gögelein, Flavio Romano, Francesco Sciortino, and Achille Giacometti &amp;quot;Fluid-fluid and fluid-solid transitions in the Kern-Frenkel model from Barker-Henderson thermodynamic perturbation theory&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 094512 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4722477 Emanuela Bianchi, Günther Doppelbauer, Laura Filion, Marjolein Dijkstra, and Gerhard Kahl &amp;quot;Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 214102 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4960423  Z. Preisler, T. Vissers, F. Smallenburg and F. Sciortino &amp;quot;Crystals of Janus colloids at various interaction ranges&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 064513 (2016)]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
[[category: models]]&lt;/div&gt;</summary>
		<author><name>128.42.195.43</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20616</id>
		<title>Kern and Frenkel patchy model</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20616"/>
		<updated>2023-09-21T00:38:29Z</updated>

		<summary type="html">&lt;p&gt;128.42.195.43: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;The &#039;&#039;&#039;Kern and Frenkel&#039;&#039;&#039; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.1569473 Norbert Kern and Daan Frenkel &amp;quot;Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction&amp;quot;, Journal of Chemical Physics 118, 9882 (2003)]&amp;lt;/ref&amp;gt; [[Patchy particles |patchy model]] published in 2003 is an amalgamation of the [[hard sphere model]] with&lt;br /&gt;
attractive [[Square well model | square well]] patches (HSSW). The model was originally developed by Bol (1982),&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1080/00268978200100461 W. Bol &amp;quot;Monte Carlo simulations of fluid systems of waterlike molecules&amp;quot;, Molecular Physics &#039;&#039;&#039;45&#039;&#039;&#039; pp. 605-616 (1982)]&amp;lt;/ref&amp;gt; and later Chapman (1988) &amp;lt;ref&amp;gt;[W.G. Chapman, Doctoral Thesis, Cornell University (1988)]&amp;lt;/ref&amp;gt; &amp;lt;ref&amp;gt;[G. Jackson, W.G. Chapman, K.E. Gubbins, Molecular Physics 65, 1-31 (1988)]&amp;lt;/ref&amp;gt; reinvented the model as the basis for numerous articles describing properties of associating particles from molecular simulation and theory. The computational advantage of Bol&#039;s model is that only a simple dot product is required to determine if a particle is in the bonding orientation. &lt;br /&gt;
 The potential has an angular aspect, given by (Eq. 1)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;\Phi_{ij}({\mathbf r}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j)  =\Phi_{ij}^{ \mathrm{HSSW}}({\mathbf r}_{ij}) \cdot f(\tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j) &amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
where the radial component is given by the square well model (Eq. 2)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\Phi_{ij}^{ \mathrm{HSSW}} \left({\mathbf r}_{ij} \right) = &lt;br /&gt;
\left\{ \begin{array}{ccc}&lt;br /&gt;
\infty &amp;amp; ; &amp;amp; r &amp;lt; \sigma \\&lt;br /&gt;
- \epsilon &amp;amp; ; &amp;amp;\sigma \le r &amp;lt; \lambda \sigma \\&lt;br /&gt;
0         &amp;amp; ; &amp;amp; r \ge \lambda \sigma \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
and the orientational component is given by (Eq. 3)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
f_{ij} \left(\hat{ {\mathbf r}}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j \right) = &lt;br /&gt;
\left\{ \begin{array}{clc}&lt;br /&gt;
1         &amp;amp; \mathrm{if}        &amp;amp; \left\{ \begin{array}{ccc}     &amp;amp;  (\hat{e}_\alpha\cdot\hat{r}_{ij} \geq \cos \delta) &amp;amp; \mathrm{for~some~patch~\alpha~on~}i  \\ &lt;br /&gt;
                                                            \mathrm{and} &amp;amp; (\hat{e}_\beta\cdot\hat{r}_{ji} \geq \cos \delta)  &amp;amp; \mathrm{for~some~patch~\beta~on~}j  \end{array} \right. \\&lt;br /&gt;
0         &amp;amp; \mathrm{otherwise} &amp;amp;  \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; is the solid angle of a patch (&amp;lt;math&amp;gt;\alpha, \beta, ...&amp;lt;/math&amp;gt;) whose axis is &amp;lt;math&amp;gt;\hat{e}&amp;lt;/math&amp;gt; (see Fig. 1 of Ref. 1), forming a conical segment.&lt;br /&gt;
==Multiple patches==&lt;br /&gt;
The &amp;quot;two-patch&amp;quot; and &amp;quot;four-patch&amp;quot; Bol (Chapman or Kern and Frenkel) model was extensively studied by Chapman and co-workers for bulk and interfacial systems using hard sphere and Lennard-Jones reference systems.  Later other groups, including Sciortino and co-workers, considered stronger association energies for the &amp;quot;two-patch&amp;quot; hard sphere reference &amp;lt;ref name=&amp;quot;bianchi&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.2730797  F. Sciortino, E. Bianchi, J. Douglas and P. Tartaglia &amp;quot;Self-assembly of patchy particles into polymer chains: A parameter-free comparison between Wertheim theory and Monte Carlo simulation&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;126&#039;&#039;&#039; 194903 (2007)]&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3415490 Achille Giacometti, Fred Lado, Julio Largo, Giorgio Pastore, and Francesco Sciortino &amp;quot;Effects of patch size and number within a simple model of patchy colloids&amp;quot;, Journal of Chemical Physics 132, 174110 (2010)]&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.4737930  José Maria Tavares, Lorenzo Rovigatti, and Francesco Sciortino &amp;quot;Quantitative description of the self-assembly of patchy particles into chains and rings&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;137&#039;&#039;&#039; 044901 (2012)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
==Four patches==&lt;br /&gt;
:&#039;&#039;Main article: [[Anisotropic particles with tetrahedral symmetry]]&#039;&#039;&lt;br /&gt;
&lt;br /&gt;
==Single-bond-per-patch-condition==&lt;br /&gt;
If the two parameters &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\lambda&amp;lt;/math&amp;gt; fullfil the condition&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\sin{\delta} \leq \dfrac{1}{2(1+\lambda\sigma)}&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
then the patch cannot be involved in more than one bond. Enforcing this condition makes it possible to compare the simulations results with [[Wertheim&#039;s first order thermodynamic perturbation theory (TPT1)| Wertheim theory]] &amp;lt;ref name=&amp;quot;bianchi&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Hard ellipsoid model==&lt;br /&gt;
The [[hard ellipsoid model]] has also been used as the &#039;nucleus&#039; of the Kern and Frenkel patchy model &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.4969074  T. N. Carpency, J. D. Gunton and J. M. Rickman &amp;quot;Phase behavior of patchy spheroidal fluids&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 214904 (2016)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
==References==&lt;br /&gt;
&amp;lt;references/&amp;gt;&lt;br /&gt;
;Related reading&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.3689308 Christoph Gögelein, Flavio Romano, Francesco Sciortino, and Achille Giacometti &amp;quot;Fluid-fluid and fluid-solid transitions in the Kern-Frenkel model from Barker-Henderson thermodynamic perturbation theory&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 094512 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4722477 Emanuela Bianchi, Günther Doppelbauer, Laura Filion, Marjolein Dijkstra, and Gerhard Kahl &amp;quot;Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 214102 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4960423  Z. Preisler, T. Vissers, F. Smallenburg and F. Sciortino &amp;quot;Crystals of Janus colloids at various interaction ranges&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 064513 (2016)]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
[[category: models]]&lt;/div&gt;</summary>
		<author><name>128.42.195.43</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20615</id>
		<title>Kern and Frenkel patchy model</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20615"/>
		<updated>2023-09-21T00:38:08Z</updated>

		<summary type="html">&lt;p&gt;128.42.195.43: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;The &#039;&#039;&#039;Kern and Frenkel&#039;&#039;&#039; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.1569473 Norbert Kern and Daan Frenkel &amp;quot;Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction&amp;quot;, Journal of Chemical Physics 118, 9882 (2003)]&amp;lt;/ref&amp;gt; [[Patchy particles |patchy model]] published in 2003 is an amalgamation of the [[hard sphere model]] with&lt;br /&gt;
attractive [[Square well model | square well]] patches (HSSW). The model was originally developed by Bol (1982),&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1080/00268978200100461 W. Bol &amp;quot;Monte Carlo simulations of fluid systems of waterlike molecules&amp;quot;, Molecular Physics &#039;&#039;&#039;45&#039;&#039;&#039; pp. 605-616 (1982)]&amp;lt;/ref&amp;gt; and later by Chapman (1988) &amp;lt;ref&amp;gt;[W.G. Chapman, Doctoral Thesis, Cornell University (1988)]&amp;lt;/ref&amp;gt; &amp;lt;ref&amp;gt;[G. Jackson, W.G. Chapman, K.E. Gubbins, Molecular Physics 65, 1-31 (1988)]&amp;lt;/ref&amp;gt; reinvented the model as the basis for numerous articles describing properties of associating particles from molecular simulation and theory. The computational advantage of Bol&#039;s model is that only a simple dot product is required to determine if a particle is in the bonding orientation. &lt;br /&gt;
 The potential has an angular aspect, given by (Eq. 1)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;\Phi_{ij}({\mathbf r}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j)  =\Phi_{ij}^{ \mathrm{HSSW}}({\mathbf r}_{ij}) \cdot f(\tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j) &amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
where the radial component is given by the square well model (Eq. 2)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\Phi_{ij}^{ \mathrm{HSSW}} \left({\mathbf r}_{ij} \right) = &lt;br /&gt;
\left\{ \begin{array}{ccc}&lt;br /&gt;
\infty &amp;amp; ; &amp;amp; r &amp;lt; \sigma \\&lt;br /&gt;
- \epsilon &amp;amp; ; &amp;amp;\sigma \le r &amp;lt; \lambda \sigma \\&lt;br /&gt;
0         &amp;amp; ; &amp;amp; r \ge \lambda \sigma \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
and the orientational component is given by (Eq. 3)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
f_{ij} \left(\hat{ {\mathbf r}}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j \right) = &lt;br /&gt;
\left\{ \begin{array}{clc}&lt;br /&gt;
1         &amp;amp; \mathrm{if}        &amp;amp; \left\{ \begin{array}{ccc}     &amp;amp;  (\hat{e}_\alpha\cdot\hat{r}_{ij} \geq \cos \delta) &amp;amp; \mathrm{for~some~patch~\alpha~on~}i  \\ &lt;br /&gt;
                                                            \mathrm{and} &amp;amp; (\hat{e}_\beta\cdot\hat{r}_{ji} \geq \cos \delta)  &amp;amp; \mathrm{for~some~patch~\beta~on~}j  \end{array} \right. \\&lt;br /&gt;
0         &amp;amp; \mathrm{otherwise} &amp;amp;  \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; is the solid angle of a patch (&amp;lt;math&amp;gt;\alpha, \beta, ...&amp;lt;/math&amp;gt;) whose axis is &amp;lt;math&amp;gt;\hat{e}&amp;lt;/math&amp;gt; (see Fig. 1 of Ref. 1), forming a conical segment.&lt;br /&gt;
==Multiple patches==&lt;br /&gt;
The &amp;quot;two-patch&amp;quot; and &amp;quot;four-patch&amp;quot; Bol (Chapman or Kern and Frenkel) model was extensively studied by Chapman and co-workers for bulk and interfacial systems using hard sphere and Lennard-Jones reference systems.  Later other groups, including Sciortino and co-workers, considered stronger association energies for the &amp;quot;two-patch&amp;quot; hard sphere reference &amp;lt;ref name=&amp;quot;bianchi&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.2730797  F. Sciortino, E. Bianchi, J. Douglas and P. Tartaglia &amp;quot;Self-assembly of patchy particles into polymer chains: A parameter-free comparison between Wertheim theory and Monte Carlo simulation&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;126&#039;&#039;&#039; 194903 (2007)]&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3415490 Achille Giacometti, Fred Lado, Julio Largo, Giorgio Pastore, and Francesco Sciortino &amp;quot;Effects of patch size and number within a simple model of patchy colloids&amp;quot;, Journal of Chemical Physics 132, 174110 (2010)]&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.4737930  José Maria Tavares, Lorenzo Rovigatti, and Francesco Sciortino &amp;quot;Quantitative description of the self-assembly of patchy particles into chains and rings&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;137&#039;&#039;&#039; 044901 (2012)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
==Four patches==&lt;br /&gt;
:&#039;&#039;Main article: [[Anisotropic particles with tetrahedral symmetry]]&#039;&#039;&lt;br /&gt;
&lt;br /&gt;
==Single-bond-per-patch-condition==&lt;br /&gt;
If the two parameters &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\lambda&amp;lt;/math&amp;gt; fullfil the condition&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\sin{\delta} \leq \dfrac{1}{2(1+\lambda\sigma)}&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
then the patch cannot be involved in more than one bond. Enforcing this condition makes it possible to compare the simulations results with [[Wertheim&#039;s first order thermodynamic perturbation theory (TPT1)| Wertheim theory]] &amp;lt;ref name=&amp;quot;bianchi&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Hard ellipsoid model==&lt;br /&gt;
The [[hard ellipsoid model]] has also been used as the &#039;nucleus&#039; of the Kern and Frenkel patchy model &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.4969074  T. N. Carpency, J. D. Gunton and J. M. Rickman &amp;quot;Phase behavior of patchy spheroidal fluids&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 214904 (2016)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
==References==&lt;br /&gt;
&amp;lt;references/&amp;gt;&lt;br /&gt;
;Related reading&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.3689308 Christoph Gögelein, Flavio Romano, Francesco Sciortino, and Achille Giacometti &amp;quot;Fluid-fluid and fluid-solid transitions in the Kern-Frenkel model from Barker-Henderson thermodynamic perturbation theory&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 094512 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4722477 Emanuela Bianchi, Günther Doppelbauer, Laura Filion, Marjolein Dijkstra, and Gerhard Kahl &amp;quot;Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 214102 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4960423  Z. Preisler, T. Vissers, F. Smallenburg and F. Sciortino &amp;quot;Crystals of Janus colloids at various interaction ranges&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 064513 (2016)]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
[[category: models]]&lt;/div&gt;</summary>
		<author><name>128.42.195.43</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20614</id>
		<title>Kern and Frenkel patchy model</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20614"/>
		<updated>2023-09-21T00:37:42Z</updated>

		<summary type="html">&lt;p&gt;128.42.195.43: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;The &#039;&#039;&#039;Kern and Frenkel&#039;&#039;&#039; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.1569473 Norbert Kern and Daan Frenkel &amp;quot;Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction&amp;quot;, Journal of Chemical Physics 118, 9882 (2003)]&amp;lt;/ref&amp;gt; [[Patchy particles |patchy model]] published in 2003 is an amalgamation of the [[hard sphere model]] with&lt;br /&gt;
attractive [[Square well model | square well]] patches (HSSW). The model was originally developed by Bol (1982),&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1080/00268978200100461 W. Bol &amp;quot;Monte Carlo simulations of fluid systems of waterlike molecules&amp;quot;, Molecular Physics &#039;&#039;&#039;45&#039;&#039;&#039; pp. 605-616 (1982)]&amp;lt;/ref&amp;gt; and later Chapman (1988) &amp;lt;ref&amp;gt;[W.G. Chapman, Doctoral Thesis, Cornell University (1988)]&amp;lt;/ref&amp;gt; &amp;lt;ref&amp;gt;[G. Jackson, W.G. Chapman, K.E. Gubbins, Molecular Physics 65, 1-31 (1988)]&amp;lt;/ref&amp;gt; reinvented the model as the basis for numerous articles describing properties of associating particles from molecular simulation and theory. The computational advantage of Bol&#039;s model is that only a simple dot product is required to determine if a particle is in the bonding orientation. &lt;br /&gt;
 The potential has an angular aspect, given by (Eq. 1)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;\Phi_{ij}({\mathbf r}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j)  =\Phi_{ij}^{ \mathrm{HSSW}}({\mathbf r}_{ij}) \cdot f(\tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j) &amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
where the radial component is given by the square well model (Eq. 2)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\Phi_{ij}^{ \mathrm{HSSW}} \left({\mathbf r}_{ij} \right) = &lt;br /&gt;
\left\{ \begin{array}{ccc}&lt;br /&gt;
\infty &amp;amp; ; &amp;amp; r &amp;lt; \sigma \\&lt;br /&gt;
- \epsilon &amp;amp; ; &amp;amp;\sigma \le r &amp;lt; \lambda \sigma \\&lt;br /&gt;
0         &amp;amp; ; &amp;amp; r \ge \lambda \sigma \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
and the orientational component is given by (Eq. 3)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
f_{ij} \left(\hat{ {\mathbf r}}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j \right) = &lt;br /&gt;
\left\{ \begin{array}{clc}&lt;br /&gt;
1         &amp;amp; \mathrm{if}        &amp;amp; \left\{ \begin{array}{ccc}     &amp;amp;  (\hat{e}_\alpha\cdot\hat{r}_{ij} \geq \cos \delta) &amp;amp; \mathrm{for~some~patch~\alpha~on~}i  \\ &lt;br /&gt;
                                                            \mathrm{and} &amp;amp; (\hat{e}_\beta\cdot\hat{r}_{ji} \geq \cos \delta)  &amp;amp; \mathrm{for~some~patch~\beta~on~}j  \end{array} \right. \\&lt;br /&gt;
0         &amp;amp; \mathrm{otherwise} &amp;amp;  \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; is the solid angle of a patch (&amp;lt;math&amp;gt;\alpha, \beta, ...&amp;lt;/math&amp;gt;) whose axis is &amp;lt;math&amp;gt;\hat{e}&amp;lt;/math&amp;gt; (see Fig. 1 of Ref. 1), forming a conical segment.&lt;br /&gt;
==Multiple patches==&lt;br /&gt;
The &amp;quot;two-patch&amp;quot; and &amp;quot;four-patch&amp;quot; Bol (Chapman or Kern and Frenkel) model was extensively studied by Chapman and co-workers for bulk and interfacial systems using hard sphere and Lennard-Jones reference systems.  Later other groups, including Sciortino and co-workers, considered stronger association energies for the &amp;quot;two-patch&amp;quot; hard sphere reference &amp;lt;ref name=&amp;quot;bianchi&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.2730797  F. Sciortino, E. Bianchi, J. Douglas and P. Tartaglia &amp;quot;Self-assembly of patchy particles into polymer chains: A parameter-free comparison between Wertheim theory and Monte Carlo simulation&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;126&#039;&#039;&#039; 194903 (2007)]&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3415490 Achille Giacometti, Fred Lado, Julio Largo, Giorgio Pastore, and Francesco Sciortino &amp;quot;Effects of patch size and number within a simple model of patchy colloids&amp;quot;, Journal of Chemical Physics 132, 174110 (2010)]&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.4737930  José Maria Tavares, Lorenzo Rovigatti, and Francesco Sciortino &amp;quot;Quantitative description of the self-assembly of patchy particles into chains and rings&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;137&#039;&#039;&#039; 044901 (2012)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
==Four patches==&lt;br /&gt;
:&#039;&#039;Main article: [[Anisotropic particles with tetrahedral symmetry]]&#039;&#039;&lt;br /&gt;
&lt;br /&gt;
==Single-bond-per-patch-condition==&lt;br /&gt;
If the two parameters &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\lambda&amp;lt;/math&amp;gt; fullfil the condition&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\sin{\delta} \leq \dfrac{1}{2(1+\lambda\sigma)}&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
then the patch cannot be involved in more than one bond. Enforcing this condition makes it possible to compare the simulations results with [[Wertheim&#039;s first order thermodynamic perturbation theory (TPT1)| Wertheim theory]] &amp;lt;ref name=&amp;quot;bianchi&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Hard ellipsoid model==&lt;br /&gt;
The [[hard ellipsoid model]] has also been used as the &#039;nucleus&#039; of the Kern and Frenkel patchy model &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.4969074  T. N. Carpency, J. D. Gunton and J. M. Rickman &amp;quot;Phase behavior of patchy spheroidal fluids&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 214904 (2016)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
==References==&lt;br /&gt;
&amp;lt;references/&amp;gt;&lt;br /&gt;
;Related reading&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.3689308 Christoph Gögelein, Flavio Romano, Francesco Sciortino, and Achille Giacometti &amp;quot;Fluid-fluid and fluid-solid transitions in the Kern-Frenkel model from Barker-Henderson thermodynamic perturbation theory&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 094512 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4722477 Emanuela Bianchi, Günther Doppelbauer, Laura Filion, Marjolein Dijkstra, and Gerhard Kahl &amp;quot;Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 214102 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4960423  Z. Preisler, T. Vissers, F. Smallenburg and F. Sciortino &amp;quot;Crystals of Janus colloids at various interaction ranges&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 064513 (2016)]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
[[category: models]]&lt;/div&gt;</summary>
		<author><name>128.42.195.43</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20613</id>
		<title>Kern and Frenkel patchy model</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20613"/>
		<updated>2023-09-21T00:36:49Z</updated>

		<summary type="html">&lt;p&gt;128.42.195.43: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;The &#039;&#039;&#039;Kern and Frenkel&#039;&#039;&#039; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.1569473 Norbert Kern and Daan Frenkel &amp;quot;Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction&amp;quot;, Journal of Chemical Physics 118, 9882 (2003)]&amp;lt;/ref&amp;gt; [[Patchy particles |patchy model]] published in 2003 is an amalgamation of the [[hard sphere model]] with&lt;br /&gt;
attractive [[Square well model | square well]] patches (HSSW). The model was originally developed by Bol (1982),&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1080/00268978200100461 W. Bol &amp;quot;Monte Carlo simulations of fluid systems of waterlike molecules&amp;quot;, Molecular Physics &#039;&#039;&#039;45&#039;&#039;&#039; pp. 605-616 (1982)]&amp;lt;/ref&amp;gt; and later Chapman(1988) &amp;lt;ref&amp;gt;[W.G. Chapman, Doctoral Thesis, Cornell University (1988)]&amp;lt;/ref&amp;gt; &amp;lt;ref&amp;gt;[G. Jackson, W.G. Chapman, K.E. Gubbins, Molecular Physics 65, 1-31 (1988)]&amp;lt;/ref&amp;gt; reinvented the model as the basis for numerous articles describing properties of associating particles from molecular simulation and theory. The computational advantage of Bol&#039;s model is that only a simple dot product is required to determine if a particle is in the bonding orientation. &lt;br /&gt;
 The potential has an angular aspect, given by (Eq. 1)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;\Phi_{ij}({\mathbf r}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j)  =\Phi_{ij}^{ \mathrm{HSSW}}({\mathbf r}_{ij}) \cdot f(\tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j) &amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
where the radial component is given by the square well model (Eq. 2)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\Phi_{ij}^{ \mathrm{HSSW}} \left({\mathbf r}_{ij} \right) = &lt;br /&gt;
\left\{ \begin{array}{ccc}&lt;br /&gt;
\infty &amp;amp; ; &amp;amp; r &amp;lt; \sigma \\&lt;br /&gt;
- \epsilon &amp;amp; ; &amp;amp;\sigma \le r &amp;lt; \lambda \sigma \\&lt;br /&gt;
0         &amp;amp; ; &amp;amp; r \ge \lambda \sigma \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
and the orientational component is given by (Eq. 3)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
f_{ij} \left(\hat{ {\mathbf r}}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j \right) = &lt;br /&gt;
\left\{ \begin{array}{clc}&lt;br /&gt;
1         &amp;amp; \mathrm{if}        &amp;amp; \left\{ \begin{array}{ccc}     &amp;amp;  (\hat{e}_\alpha\cdot\hat{r}_{ij} \geq \cos \delta) &amp;amp; \mathrm{for~some~patch~\alpha~on~}i  \\ &lt;br /&gt;
                                                            \mathrm{and} &amp;amp; (\hat{e}_\beta\cdot\hat{r}_{ji} \geq \cos \delta)  &amp;amp; \mathrm{for~some~patch~\beta~on~}j  \end{array} \right. \\&lt;br /&gt;
0         &amp;amp; \mathrm{otherwise} &amp;amp;  \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; is the solid angle of a patch (&amp;lt;math&amp;gt;\alpha, \beta, ...&amp;lt;/math&amp;gt;) whose axis is &amp;lt;math&amp;gt;\hat{e}&amp;lt;/math&amp;gt; (see Fig. 1 of Ref. 1), forming a conical segment.&lt;br /&gt;
==Multiple patches==&lt;br /&gt;
The &amp;quot;two-patch&amp;quot; and &amp;quot;four-patch&amp;quot; Bol (Chapman or Kern and Frenkel) model was extensively studied by Chapman and co-workers for bulk and interfacial systems using hard sphere and Lennard-Jones reference systems.  Later other groups, including Sciortino and co-workers, considered stronger association energies for the &amp;quot;two-patch&amp;quot; hard sphere reference &amp;lt;ref name=&amp;quot;bianchi&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.2730797  F. Sciortino, E. Bianchi, J. Douglas and P. Tartaglia &amp;quot;Self-assembly of patchy particles into polymer chains: A parameter-free comparison between Wertheim theory and Monte Carlo simulation&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;126&#039;&#039;&#039; 194903 (2007)]&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3415490 Achille Giacometti, Fred Lado, Julio Largo, Giorgio Pastore, and Francesco Sciortino &amp;quot;Effects of patch size and number within a simple model of patchy colloids&amp;quot;, Journal of Chemical Physics 132, 174110 (2010)]&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.4737930  José Maria Tavares, Lorenzo Rovigatti, and Francesco Sciortino &amp;quot;Quantitative description of the self-assembly of patchy particles into chains and rings&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;137&#039;&#039;&#039; 044901 (2012)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
==Four patches==&lt;br /&gt;
:&#039;&#039;Main article: [[Anisotropic particles with tetrahedral symmetry]]&#039;&#039;&lt;br /&gt;
&lt;br /&gt;
==Single-bond-per-patch-condition==&lt;br /&gt;
If the two parameters &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\lambda&amp;lt;/math&amp;gt; fullfil the condition&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\sin{\delta} \leq \dfrac{1}{2(1+\lambda\sigma)}&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
then the patch cannot be involved in more than one bond. Enforcing this condition makes it possible to compare the simulations results with [[Wertheim&#039;s first order thermodynamic perturbation theory (TPT1)| Wertheim theory]] &amp;lt;ref name=&amp;quot;bianchi&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Hard ellipsoid model==&lt;br /&gt;
The [[hard ellipsoid model]] has also been used as the &#039;nucleus&#039; of the Kern and Frenkel patchy model &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.4969074  T. N. Carpency, J. D. Gunton and J. M. Rickman &amp;quot;Phase behavior of patchy spheroidal fluids&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 214904 (2016)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
==References==&lt;br /&gt;
&amp;lt;references/&amp;gt;&lt;br /&gt;
;Related reading&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.3689308 Christoph Gögelein, Flavio Romano, Francesco Sciortino, and Achille Giacometti &amp;quot;Fluid-fluid and fluid-solid transitions in the Kern-Frenkel model from Barker-Henderson thermodynamic perturbation theory&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 094512 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4722477 Emanuela Bianchi, Günther Doppelbauer, Laura Filion, Marjolein Dijkstra, and Gerhard Kahl &amp;quot;Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 214102 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4960423  Z. Preisler, T. Vissers, F. Smallenburg and F. Sciortino &amp;quot;Crystals of Janus colloids at various interaction ranges&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 064513 (2016)]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
[[category: models]]&lt;/div&gt;</summary>
		<author><name>128.42.195.43</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20612</id>
		<title>Kern and Frenkel patchy model</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20612"/>
		<updated>2023-09-21T00:35:36Z</updated>

		<summary type="html">&lt;p&gt;128.42.195.43: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;The &#039;&#039;&#039;Kern and Frenkel&#039;&#039;&#039; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.1569473 Norbert Kern and Daan Frenkel &amp;quot;Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction&amp;quot;, Journal of Chemical Physics 118, 9882 (2003)]&amp;lt;/ref&amp;gt; [[Patchy particles |patchy model]] published in 2003 is an amalgamation of the [[hard sphere model]] with&lt;br /&gt;
attractive [[Square well model | square well]] patches (HSSW). The model was originally developed by Bol (1982),&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1080/00268978200100461 W. Bol &amp;quot;Monte Carlo simulations of fluid systems of waterlike molecules&amp;quot;, Molecular Physics &#039;&#039;&#039;45&#039;&#039;&#039; pp. 605-616 (1982)]&amp;lt;/ref&amp;gt; and later Chapman(1988) &amp;lt;ref&amp;gt;[W.G. Chapman, Doctoral Thesis, Cornell University (1988)]&amp;lt;/ref&amp;gt; &amp;lt;ref&amp;gt;[G. Jackson, W.G. Chapman, K.E. Gubbins, Molecular Physics 65, 1-31 (1988)]&amp;lt;/ref&amp;gt; reinvented the model as the basis for numerous articles describing properties of associating particles from molecular simulation and theory. The computational advantage of Bol&#039;s model is that only a simple dot product is required to determine if a particle is in the bonding orientation. &lt;br /&gt;
 The potential has an angular aspect, given by (Eq. 1)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;\Phi_{ij}({\mathbf r}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j)  =\Phi_{ij}^{ \mathrm{HSSW}}({\mathbf r}_{ij}) \cdot f(\tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j) &amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
where the radial component is given by the square well model (Eq. 2)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\Phi_{ij}^{ \mathrm{HSSW}} \left({\mathbf r}_{ij} \right) = &lt;br /&gt;
\left\{ \begin{array}{ccc}&lt;br /&gt;
\infty &amp;amp; ; &amp;amp; r &amp;lt; \sigma \\&lt;br /&gt;
- \epsilon &amp;amp; ; &amp;amp;\sigma \le r &amp;lt; \lambda \sigma \\&lt;br /&gt;
0         &amp;amp; ; &amp;amp; r \ge \lambda \sigma \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
and the orientational component is given by (Eq. 3)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
f_{ij} \left(\hat{ {\mathbf r}}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j \right) = &lt;br /&gt;
\left\{ \begin{array}{clc}&lt;br /&gt;
1         &amp;amp; \mathrm{if}        &amp;amp; \left\{ \begin{array}{ccc}     &amp;amp;  (\hat{e}_\alpha\cdot\hat{r}_{ij} \geq \cos \delta) &amp;amp; \mathrm{for~some~patch~\alpha~on~}i  \\ &lt;br /&gt;
                                                            \mathrm{and} &amp;amp; (\hat{e}_\beta\cdot\hat{r}_{ji} \geq \cos \delta)  &amp;amp; \mathrm{for~some~patch~\beta~on~}j  \end{array} \right. \\&lt;br /&gt;
0         &amp;amp; \mathrm{otherwise} &amp;amp;  \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; is the solid angle of a patch (&amp;lt;math&amp;gt;\alpha, \beta, ...&amp;lt;/math&amp;gt;) whose axis is &amp;lt;math&amp;gt;\hat{e}&amp;lt;/math&amp;gt; (see Fig. 1 of Ref. 1), forming a conical segment.&lt;br /&gt;
==Multiple patches==&lt;br /&gt;
The &amp;quot;two-patch&amp;quot; and &amp;quot;four-patch&amp;quot; Bol (Chapman or Kern and Frenkel) model was extensively studied by Chapman and co-workers for bulk and interfacial systems using hard sphere and Lennard-Jones references.  Later other groups, including Sciortino and co-workers, considered stronger association energies for the &amp;quot;two-patch&amp;quot; hard sphere reference &amp;lt;ref name=&amp;quot;bianchi&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.2730797  F. Sciortino, E. Bianchi, J. Douglas and P. Tartaglia &amp;quot;Self-assembly of patchy particles into polymer chains: A parameter-free comparison between Wertheim theory and Monte Carlo simulation&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;126&#039;&#039;&#039; 194903 (2007)]&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3415490 Achille Giacometti, Fred Lado, Julio Largo, Giorgio Pastore, and Francesco Sciortino &amp;quot;Effects of patch size and number within a simple model of patchy colloids&amp;quot;, Journal of Chemical Physics 132, 174110 (2010)]&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.4737930  José Maria Tavares, Lorenzo Rovigatti, and Francesco Sciortino &amp;quot;Quantitative description of the self-assembly of patchy particles into chains and rings&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;137&#039;&#039;&#039; 044901 (2012)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
==Four patches==&lt;br /&gt;
:&#039;&#039;Main article: [[Anisotropic particles with tetrahedral symmetry]]&#039;&#039;&lt;br /&gt;
&lt;br /&gt;
==Single-bond-per-patch-condition==&lt;br /&gt;
If the two parameters &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\lambda&amp;lt;/math&amp;gt; fullfil the condition&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\sin{\delta} \leq \dfrac{1}{2(1+\lambda\sigma)}&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
then the patch cannot be involved in more than one bond. Enforcing this condition makes it possible to compare the simulations results with [[Wertheim&#039;s first order thermodynamic perturbation theory (TPT1)| Wertheim theory]] &amp;lt;ref name=&amp;quot;bianchi&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Hard ellipsoid model==&lt;br /&gt;
The [[hard ellipsoid model]] has also been used as the &#039;nucleus&#039; of the Kern and Frenkel patchy model &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.4969074  T. N. Carpency, J. D. Gunton and J. M. Rickman &amp;quot;Phase behavior of patchy spheroidal fluids&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 214904 (2016)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
==References==&lt;br /&gt;
&amp;lt;references/&amp;gt;&lt;br /&gt;
;Related reading&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.3689308 Christoph Gögelein, Flavio Romano, Francesco Sciortino, and Achille Giacometti &amp;quot;Fluid-fluid and fluid-solid transitions in the Kern-Frenkel model from Barker-Henderson thermodynamic perturbation theory&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 094512 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4722477 Emanuela Bianchi, Günther Doppelbauer, Laura Filion, Marjolein Dijkstra, and Gerhard Kahl &amp;quot;Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 214102 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4960423  Z. Preisler, T. Vissers, F. Smallenburg and F. Sciortino &amp;quot;Crystals of Janus colloids at various interaction ranges&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 064513 (2016)]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
[[category: models]]&lt;/div&gt;</summary>
		<author><name>128.42.195.43</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20611</id>
		<title>Kern and Frenkel patchy model</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Kern_and_Frenkel_patchy_model&amp;diff=20611"/>
		<updated>2023-09-21T00:25:41Z</updated>

		<summary type="html">&lt;p&gt;128.42.195.43: &lt;/p&gt;
&lt;hr /&gt;
&lt;div&gt;The &#039;&#039;&#039;Kern and Frenkel&#039;&#039;&#039; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.1569473 Norbert Kern and Daan Frenkel &amp;quot;Fluid–fluid coexistence in colloidal systems with short-ranged strongly directional attraction&amp;quot;, Journal of Chemical Physics 118, 9882 (2003)]&amp;lt;/ref&amp;gt; [[Patchy particles |patchy model]] is an amalgamation of the [[hard sphere model]] with&lt;br /&gt;
attractive [[Square well model | square well]] patches (HSSW). The model was originally developed by Bol (1982) &amp;lt;ref&amp;gt;[W. Bol, Molecular Physics 45, 605 (1982)]&amp;lt;/ref&amp;gt; and later reinvented by Chapman (1988) &amp;lt;ref&amp;gt;[W.G. Chapman, Doctoral Thesis, Cornell University (1988)]&amp;lt;/ref&amp;gt; &amp;lt;ref&amp;gt;[G. Jackson, W.G. Chapman, K.E. Gubbins, Molecular Physics 65, 1-31 (1988)]&amp;lt;/ref&amp;gt; as the basis for numerous articles describing properties of associating particles from molecular simulation and theory. The computational advantage of Bol&#039;s model is that only a simple dot product is required to determine if a particle is in the bonding orientation. &lt;br /&gt;
 The potential has an angular aspect, given by (Eq. 1)&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;\Phi_{ij}({\mathbf r}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j)  =\Phi_{ij}^{ \mathrm{HSSW}}({\mathbf r}_{ij}) \cdot f(\tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j) &amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
where the radial component is given by the square well model (Eq. 2)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\Phi_{ij}^{ \mathrm{HSSW}} \left({\mathbf r}_{ij} \right) = &lt;br /&gt;
\left\{ \begin{array}{ccc}&lt;br /&gt;
\infty &amp;amp; ; &amp;amp; r &amp;lt; \sigma \\&lt;br /&gt;
- \epsilon &amp;amp; ; &amp;amp;\sigma \le r &amp;lt; \lambda \sigma \\&lt;br /&gt;
0         &amp;amp; ; &amp;amp; r \ge \lambda \sigma \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
and the orientational component is given by (Eq. 3)&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
f_{ij} \left(\hat{ {\mathbf r}}_{ij}; \tilde{ {\mathbf \Omega}}_i, \tilde{ {\mathbf \Omega}}_j \right) = &lt;br /&gt;
\left\{ \begin{array}{clc}&lt;br /&gt;
1         &amp;amp; \mathrm{if}        &amp;amp; \left\{ \begin{array}{ccc}     &amp;amp;  (\hat{e}_\alpha\cdot\hat{r}_{ij} \geq \cos \delta) &amp;amp; \mathrm{for~some~patch~\alpha~on~}i  \\ &lt;br /&gt;
                                                            \mathrm{and} &amp;amp; (\hat{e}_\beta\cdot\hat{r}_{ji} \geq \cos \delta)  &amp;amp; \mathrm{for~some~patch~\beta~on~}j  \end{array} \right. \\&lt;br /&gt;
0         &amp;amp; \mathrm{otherwise} &amp;amp;  \end{array} \right.&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
where &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; is the solid angle of a patch (&amp;lt;math&amp;gt;\alpha, \beta, ...&amp;lt;/math&amp;gt;) whose axis is &amp;lt;math&amp;gt;\hat{e}&amp;lt;/math&amp;gt; (see Fig. 1 of Ref. 1), forming a conical segment.&lt;br /&gt;
==Multiple patches==&lt;br /&gt;
The &amp;quot;two-patch&amp;quot; and &amp;quot;four-patch&amp;quot; Bol (Chapman or Kern and Frenkel) model was extensively studied by Chapman and co-workers for bulk and interfacial systems using hard sphere and Lennard-Jones references.  Later other groups, including Sciortino and co-workers, considered stronger association energies for the &amp;quot;two-patch&amp;quot; hard sphere reference &amp;lt;ref name=&amp;quot;bianchi&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.2730797  F. Sciortino, E. Bianchi, J. Douglas and P. Tartaglia &amp;quot;Self-assembly of patchy particles into polymer chains: A parameter-free comparison between Wertheim theory and Monte Carlo simulation&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;126&#039;&#039;&#039; 194903 (2007)]&amp;lt;/ref&amp;gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3415490 Achille Giacometti, Fred Lado, Julio Largo, Giorgio Pastore, and Francesco Sciortino &amp;quot;Effects of patch size and number within a simple model of patchy colloids&amp;quot;, Journal of Chemical Physics 132, 174110 (2010)]&amp;lt;/ref&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;&amp;gt;[http://dx.doi.org/10.1063/1.4737930  José Maria Tavares, Lorenzo Rovigatti, and Francesco Sciortino &amp;quot;Quantitative description of the self-assembly of patchy particles into chains and rings&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;137&#039;&#039;&#039; 044901 (2012)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
&lt;br /&gt;
==Four patches==&lt;br /&gt;
:&#039;&#039;Main article: [[Anisotropic particles with tetrahedral symmetry]]&#039;&#039;&lt;br /&gt;
&lt;br /&gt;
==Single-bond-per-patch-condition==&lt;br /&gt;
If the two parameters &amp;lt;math&amp;gt;\delta&amp;lt;/math&amp;gt; and &amp;lt;math&amp;gt;\lambda&amp;lt;/math&amp;gt; fullfil the condition&lt;br /&gt;
&lt;br /&gt;
:&amp;lt;math&amp;gt;&lt;br /&gt;
\sin{\delta} \leq \dfrac{1}{2(1+\lambda\sigma)}&lt;br /&gt;
&amp;lt;/math&amp;gt;&lt;br /&gt;
&lt;br /&gt;
then the patch cannot be involved in more than one bond. Enforcing this condition makes it possible to compare the simulations results with [[Wertheim&#039;s first order thermodynamic perturbation theory (TPT1)| Wertheim theory]] &amp;lt;ref name=&amp;quot;bianchi&amp;quot;/&amp;gt;&amp;lt;ref name=&amp;quot;rovigatti&amp;quot;/&amp;gt;&lt;br /&gt;
&lt;br /&gt;
==Hard ellipsoid model==&lt;br /&gt;
The [[hard ellipsoid model]] has also been used as the &#039;nucleus&#039; of the Kern and Frenkel patchy model &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.4969074  T. N. Carpency, J. D. Gunton and J. M. Rickman &amp;quot;Phase behavior of patchy spheroidal fluids&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 214904 (2016)]&amp;lt;/ref&amp;gt;.&lt;br /&gt;
==References==&lt;br /&gt;
&amp;lt;references/&amp;gt;&lt;br /&gt;
;Related reading&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.3689308 Christoph Gögelein, Flavio Romano, Francesco Sciortino, and Achille Giacometti &amp;quot;Fluid-fluid and fluid-solid transitions in the Kern-Frenkel model from Barker-Henderson thermodynamic perturbation theory&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 094512 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4722477 Emanuela Bianchi, Günther Doppelbauer, Laura Filion, Marjolein Dijkstra, and Gerhard Kahl &amp;quot;Predicting patchy particle crystals: Variable box shape simulations and evolutionary algorithms&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 214102 (2012)]&lt;br /&gt;
*[http://dx.doi.org/10.1063/1.4960423  Z. Preisler, T. Vissers, F. Smallenburg and F. Sciortino &amp;quot;Crystals of Janus colloids at various interaction ranges&amp;quot;, Journal of Chemical Physics &#039;&#039;&#039;145&#039;&#039;&#039; 064513 (2016)]&lt;br /&gt;
&lt;br /&gt;
&lt;br /&gt;
[[category: models]]&lt;/div&gt;</summary>
		<author><name>128.42.195.43</name></author>
	</entry>
</feed>