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	<title>Hard disk model - Revision history</title>
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	<updated>2026-04-29T12:19:40Z</updated>
	<subtitle>Revision history for this page on the wiki</subtitle>
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		<title>90.92.206.1: /* Phase transitions */</title>
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		<updated>2022-09-29T21:12:11Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Phase transitions&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 23:12, 29 September 2022&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l10&quot;&gt;Line 10:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 10:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &quot;Phase Transition in Elastic Disks&quot;, Physical Review &#039;&#039;&#039;127&#039;&#039;&#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. Recent works show a phase diagram containing an isotropic, a hexatic, and a solid phase &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;. Highly efficient event-chain Monte Carlo simulations of over 1 million hard disks by Bernard and Krauth have solidified this picture, with a first-order phase transition between the fluid and hexatic phase at &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;packing fraction &lt;/del&gt;&amp;lt;math&amp;gt;\eta = 0.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;700&lt;/del&gt;&amp;lt;/math&amp;gt;, and a continuous transition between the hexatic and solid phases at  &amp;lt;math&amp;gt;\eta = 0.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;716&lt;/del&gt;&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[https://doi.org/10.1103/PhysRevLett.107.155704 E. P. Bernard and W. Krauth &quot;Two-Step Melting in Two Dimensions: First-Order Liquid-Hexatic Transition&quot;, Physical Review Letters &#039;&#039;&#039;107&#039;&#039;&#039; 155704  (2011)]&amp;lt;/ref&amp;gt;. Note that the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;. This scenario has since been confirmed using a variety of simulation methods &amp;lt;ref&amp;gt;[https://doi.org/10.1103/PhysRevLett.107.155704 M. Engel, J. A. Anderson, S. C. Glotzer, M. Tsobe, E. P. Bernard, and W. Krauth &quot;Hard-disk equation of state: First-order liquid-hexatic transition in two dimensions with three simulation methods&quot;, Physical Review E &#039;&#039;&#039;87&#039;&#039;&#039; 042134 (2013)]&amp;lt;/ref&amp;gt;.  &lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &quot;Phase Transition in Elastic Disks&quot;, Physical Review &#039;&#039;&#039;127&#039;&#039;&#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. Recent works show a phase diagram containing an isotropic, a hexatic, and a solid phase &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;. Highly efficient event-chain Monte Carlo simulations of over 1 million hard disks by Bernard and Krauth have solidified this picture, with a first-order phase transition between the fluid &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;at packing fraction &amp;lt;math&amp;gt;\eta = 0.700&amp;lt;/math&amp;gt; &lt;/ins&gt;and &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;the &lt;/ins&gt;hexatic phase at &amp;lt;math&amp;gt;\eta = 0.&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;716&lt;/ins&gt;&amp;lt;/math&amp;gt;, and a continuous transition between the hexatic and solid phases at  &amp;lt;math&amp;gt;\eta = 0.&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;720&lt;/ins&gt;&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[https://doi.org/10.1103/PhysRevLett.107.155704 E. P. Bernard and W. Krauth &quot;Two-Step Melting in Two Dimensions: First-Order Liquid-Hexatic Transition&quot;, Physical Review Letters &#039;&#039;&#039;107&#039;&#039;&#039; 155704  (2011)]&amp;lt;/ref&amp;gt;. Note that the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;. This scenario has since been confirmed using a variety of simulation methods &amp;lt;ref&amp;gt;[https://doi.org/10.1103/PhysRevLett.107.155704 M. Engel, J. A. Anderson, S. C. Glotzer, M. Tsobe, E. P. Bernard, and W. Krauth &quot;Hard-disk equation of state: First-order liquid-hexatic transition in two dimensions with three simulation methods&quot;, Physical Review E &#039;&#039;&#039;87&#039;&#039;&#039; 042134 (2013)]&amp;lt;/ref&amp;gt;.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &amp;quot;Prediction of a structural transition in the hard disk fluid&amp;quot;, Journal of Chemical Physics &amp;#039;&amp;#039;&amp;#039;133&amp;#039;&amp;#039;&amp;#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &amp;quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&amp;quot;, Journal of Physical Chemistry B &amp;#039;&amp;#039;&amp;#039;112&amp;#039;&amp;#039;&amp;#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;. Also studied via [[integral equations]] &amp;lt;ref&amp;gt;[https://doi.org/10.1063/1.5026496  Luis Mier-y-Terán, Brian Ignacio Machorro-Martínez, Gustavo A. Chapela, and Fernando del Río &amp;quot;Study of the hard-disk system at high densities: the fluid-hexatic phase transition&amp;quot;, Journal of Chemical Physics &amp;#039;&amp;#039;&amp;#039;148&amp;#039;&amp;#039;&amp;#039; 234502 (2018)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &amp;quot;Prediction of a structural transition in the hard disk fluid&amp;quot;, Journal of Chemical Physics &amp;#039;&amp;#039;&amp;#039;133&amp;#039;&amp;#039;&amp;#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &amp;quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&amp;quot;, Journal of Physical Chemistry B &amp;#039;&amp;#039;&amp;#039;112&amp;#039;&amp;#039;&amp;#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;. Also studied via [[integral equations]] &amp;lt;ref&amp;gt;[https://doi.org/10.1063/1.5026496  Luis Mier-y-Terán, Brian Ignacio Machorro-Martínez, Gustavo A. Chapela, and Fernando del Río &amp;quot;Study of the hard-disk system at high densities: the fluid-hexatic phase transition&amp;quot;, Journal of Chemical Physics &amp;#039;&amp;#039;&amp;#039;148&amp;#039;&amp;#039;&amp;#039; 234502 (2018)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>90.92.206.1</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=20576&amp;oldid=prev</id>
		<title>129.175.83.190: /* Phase transitions */</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=20576&amp;oldid=prev"/>
		<updated>2022-09-29T15:41:29Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Phase transitions&lt;/span&gt;&lt;/span&gt;&lt;/p&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 17:41, 29 September 2022&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l10&quot;&gt;Line 10:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 10:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &quot;Phase Transition in Elastic Disks&quot;, Physical Review &#039;&#039;&#039;127&#039;&#039;&#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;In &lt;/del&gt;a &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;recent publication by Mak &lt;/del&gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt; &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt; using &lt;/del&gt;over &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;4 &lt;/del&gt;million &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to &lt;/del&gt;have the phase &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;diagram isotropic &lt;/del&gt;&amp;lt;math&amp;gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;(&lt;/del&gt;\eta &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt; &lt;/del&gt;0.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;699)&lt;/del&gt;&amp;lt;/math&amp;gt;, a &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt; &lt;/del&gt;hexatic &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;phase, &lt;/del&gt;and &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;a &lt;/del&gt;solid &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;phase &lt;/del&gt;&amp;lt;math&amp;gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;(&lt;/del&gt;\eta &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;gt; &lt;/del&gt;0.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;723)&lt;/del&gt;&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&quot;, Journal of Physical Chemistry B &#039;&#039;&#039;112&#039;&#039;&#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;. Also studied via [[integral equations]] &amp;lt;ref&amp;gt;[https://doi.org/10.1063/1.5026496  Luis Mier-y-Terán, Brian Ignacio Machorro-Martínez, Gustavo A. Chapela, and Fernando del Río &quot;Study of the hard-disk system at high densities: the fluid-hexatic phase transition&quot;, Journal of Chemical Physics &#039;&#039;&#039;148&#039;&#039;&#039; 234502 (2018)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &quot;Phase Transition in Elastic Disks&quot;, Physical Review &#039;&#039;&#039;127&#039;&#039;&#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Recent works show &lt;/ins&gt;a &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;phase diagram containing an isotropic, a hexatic, and a solid phase &lt;/ins&gt;&amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. Highly efficient event-chain Monte Carlo simulations of &lt;/ins&gt;over &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;1 &lt;/ins&gt;million &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;hard disks by Bernard and Krauth &lt;/ins&gt;have &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;solidified this picture, with a first-order phase transition between &lt;/ins&gt;the &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;fluid and hexatic &lt;/ins&gt;phase &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;at packing fraction &lt;/ins&gt;&amp;lt;math&amp;gt;\eta &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;= &lt;/ins&gt;0.&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;700&lt;/ins&gt;&amp;lt;/math&amp;gt;, &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;and &lt;/ins&gt;a &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;continuous transition between the &lt;/ins&gt;hexatic and solid &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;phases at  &lt;/ins&gt;&amp;lt;math&amp;gt;\eta &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;= &lt;/ins&gt;0.&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;716&lt;/ins&gt;&amp;lt;/math&amp;gt; &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&amp;lt;ref&amp;gt;[https://doi.org/10.1103/PhysRevLett.107.155704 E. P. Bernard and W. Krauth &quot;Two-Step Melting in Two Dimensions: First-Order Liquid-Hexatic Transition&quot;, Physical Review Letters &#039;&#039;&#039;107&#039;&#039;&#039; 155704  &lt;/ins&gt;(&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;2011)]&amp;lt;/ref&amp;gt;. Note that &lt;/ins&gt;the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;. This scenario has since been confirmed using a variety of simulation methods &amp;lt;ref&amp;gt;[https://doi.org/10.1103/PhysRevLett.107.155704 M. Engel, J. A. Anderson, S. C. Glotzer, M. Tsobe, E. P. Bernard, and W. Krauth &quot;Hard-disk equation of state: First-order liquid-hexatic transition in two dimensions with three simulation methods&quot;, Physical Review E &#039;&#039;&#039;87&#039;&#039;&#039; 042134 (2013&lt;/ins&gt;)&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;]&amp;lt;/ref&amp;gt;&lt;/ins&gt;.  &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&quot;, Journal of Physical Chemistry B &#039;&#039;&#039;112&#039;&#039;&#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;. Also studied via [[integral equations]] &amp;lt;ref&amp;gt;[https://doi.org/10.1063/1.5026496  Luis Mier-y-Terán, Brian Ignacio Machorro-Martínez, Gustavo A. Chapela, and Fernando del Río &quot;Study of the hard-disk system at high densities: the fluid-hexatic phase transition&quot;, Journal of Chemical Physics &#039;&#039;&#039;148&#039;&#039;&#039; 234502 (2018)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Experimental results &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevLett.118.158001 Alice L. Thorneywork, Joshua L. Abbott, Dirk G. A. L. Aarts, and Roel P. A. Dullens &amp;quot;Two-Dimensional Melting of Colloidal Hard Spheres&amp;quot;, Physical Review Letters &amp;#039;&amp;#039;&amp;#039;118&amp;#039;&amp;#039;&amp;#039; 158001 (2017)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Experimental results &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevLett.118.158001 Alice L. Thorneywork, Joshua L. Abbott, Dirk G. A. L. Aarts, and Roel P. A. Dullens &amp;quot;Two-Dimensional Melting of Colloidal Hard Spheres&amp;quot;, Physical Review Letters &amp;#039;&amp;#039;&amp;#039;118&amp;#039;&amp;#039;&amp;#039; 158001 (2017)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>129.175.83.190</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=20105&amp;oldid=prev</id>
		<title>Carl McBride: /* Phase transitions */  Added a recent publication</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=20105&amp;oldid=prev"/>
		<updated>2018-06-25T09:45:32Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Phase transitions: &lt;/span&gt;  Added a recent publication&lt;/span&gt;&lt;/p&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 11:45, 25 June 2018&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l10&quot;&gt;Line 10:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 10:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &quot;Phase Transition in Elastic Disks&quot;, Physical Review &#039;&#039;&#039;127&#039;&#039;&#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\eta &amp;lt; 0.699)&amp;lt;/math&amp;gt;, a  hexatic phase, and a solid phase &amp;lt;math&amp;gt;(\eta &amp;gt; 0.723)&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&quot;, Journal of Physical Chemistry B &#039;&#039;&#039;112&#039;&#039;&#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &quot;Phase Transition in Elastic Disks&quot;, Physical Review &#039;&#039;&#039;127&#039;&#039;&#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\eta &amp;lt; 0.699)&amp;lt;/math&amp;gt;, a  hexatic phase, and a solid phase &amp;lt;math&amp;gt;(\eta &amp;gt; 0.723)&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&quot;, Journal of Physical Chemistry B &#039;&#039;&#039;112&#039;&#039;&#039; pp. 16059-16069 (2008&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;)]&amp;lt;/ref&amp;gt;. Also studied via [[integral equations]] &amp;lt;ref&amp;gt;[https://doi.org/10.1063/1.5026496  Luis Mier-y-Terán, Brian Ignacio Machorro-Martínez, Gustavo A. Chapela, and Fernando del Río &quot;Study of the hard-disk system at high densities: the fluid-hexatic phase transition&quot;, Journal of Chemical Physics &#039;&#039;&#039;148&#039;&#039;&#039; 234502 (2018&lt;/ins&gt;)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Experimental results &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevLett.118.158001 Alice L. Thorneywork, Joshua L. Abbott, Dirk G. A. L. Aarts, and Roel P. A. Dullens &amp;quot;Two-Dimensional Melting of Colloidal Hard Spheres&amp;quot;, Physical Review Letters &amp;#039;&amp;#039;&amp;#039;118&amp;#039;&amp;#039;&amp;#039; 158001 (2017)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Experimental results &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevLett.118.158001 Alice L. Thorneywork, Joshua L. Abbott, Dirk G. A. L. Aarts, and Roel P. A. Dullens &amp;quot;Two-Dimensional Melting of Colloidal Hard Spheres&amp;quot;, Physical Review Letters &amp;#039;&amp;#039;&amp;#039;118&amp;#039;&amp;#039;&amp;#039; 158001 (2017)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Carl McBride</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=19534&amp;oldid=prev</id>
		<title>Carl McBride: /* Phase transitions */  Added a recent publication</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=19534&amp;oldid=prev"/>
		<updated>2017-04-24T10:16:25Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Phase transitions: &lt;/span&gt;  Added a recent publication&lt;/span&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 12:16, 24 April 2017&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l11&quot;&gt;Line 11:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 11:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &amp;quot;Phase Transition in Elastic Disks&amp;quot;, Physical Review &amp;#039;&amp;#039;&amp;#039;127&amp;#039;&amp;#039;&amp;#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &amp;quot;Large-scale simulations of the two-dimensional melting of hard disks&amp;quot;, Physical Review E &amp;#039;&amp;#039;&amp;#039;73&amp;#039;&amp;#039;&amp;#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\eta &amp;lt; 0.699)&amp;lt;/math&amp;gt;, a  hexatic phase, and a solid phase &amp;lt;math&amp;gt;(\eta &amp;gt; 0.723)&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &amp;quot;Über einen geometrischen Satz.&amp;quot; Mathematische Zeitschrift &amp;#039;&amp;#039;&amp;#039;46&amp;#039;&amp;#039;&amp;#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &amp;quot;Prediction of a structural transition in the hard disk fluid&amp;quot;, Journal of Chemical Physics &amp;#039;&amp;#039;&amp;#039;133&amp;#039;&amp;#039;&amp;#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &amp;quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&amp;quot;, Journal of Physical Chemistry B &amp;#039;&amp;#039;&amp;#039;112&amp;#039;&amp;#039;&amp;#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &amp;quot;Phase Transition in Elastic Disks&amp;quot;, Physical Review &amp;#039;&amp;#039;&amp;#039;127&amp;#039;&amp;#039;&amp;#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &amp;quot;Large-scale simulations of the two-dimensional melting of hard disks&amp;quot;, Physical Review E &amp;#039;&amp;#039;&amp;#039;73&amp;#039;&amp;#039;&amp;#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\eta &amp;lt; 0.699)&amp;lt;/math&amp;gt;, a  hexatic phase, and a solid phase &amp;lt;math&amp;gt;(\eta &amp;gt; 0.723)&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &amp;quot;Über einen geometrischen Satz.&amp;quot; Mathematische Zeitschrift &amp;#039;&amp;#039;&amp;#039;46&amp;#039;&amp;#039;&amp;#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &amp;quot;Prediction of a structural transition in the hard disk fluid&amp;quot;, Journal of Chemical Physics &amp;#039;&amp;#039;&amp;#039;133&amp;#039;&amp;#039;&amp;#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &amp;quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&amp;quot;, Journal of Physical Chemistry B &amp;#039;&amp;#039;&amp;#039;112&amp;#039;&amp;#039;&amp;#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Experimental results &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevLett.118.158001 Alice L. Thorneywork, Joshua L. Abbott, Dirk G. A. L. Aarts, and Roel P. A. Dullens &quot;Two-Dimensional Melting of Colloidal Hard Spheres&quot;, Physical Review Letters &#039;&#039;&#039;118&#039;&#039;&#039; 158001 (2017)]&amp;lt;/ref&amp;gt;.&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;:&amp;#039;&amp;#039;Main article: [[Equations of state for hard disks]]&amp;#039;&amp;#039;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;:&amp;#039;&amp;#039;Main article: [[Equations of state for hard disks]]&amp;#039;&amp;#039;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Carl McBride</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=14760&amp;oldid=prev</id>
		<title>Carl McBride: Added a see also section</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=14760&amp;oldid=prev"/>
		<updated>2015-10-01T12:05:15Z</updated>

		<summary type="html">&lt;p&gt;Added a see also section&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
				&lt;col class=&quot;diff-content&quot; /&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 14:05, 1 October 2015&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l11&quot;&gt;Line 11:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 11:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &amp;quot;Phase Transition in Elastic Disks&amp;quot;, Physical Review &amp;#039;&amp;#039;&amp;#039;127&amp;#039;&amp;#039;&amp;#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &amp;quot;Large-scale simulations of the two-dimensional melting of hard disks&amp;quot;, Physical Review E &amp;#039;&amp;#039;&amp;#039;73&amp;#039;&amp;#039;&amp;#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\eta &amp;lt; 0.699)&amp;lt;/math&amp;gt;, a  hexatic phase, and a solid phase &amp;lt;math&amp;gt;(\eta &amp;gt; 0.723)&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &amp;quot;Über einen geometrischen Satz.&amp;quot; Mathematische Zeitschrift &amp;#039;&amp;#039;&amp;#039;46&amp;#039;&amp;#039;&amp;#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &amp;quot;Prediction of a structural transition in the hard disk fluid&amp;quot;, Journal of Chemical Physics &amp;#039;&amp;#039;&amp;#039;133&amp;#039;&amp;#039;&amp;#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &amp;quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&amp;quot;, Journal of Physical Chemistry B &amp;#039;&amp;#039;&amp;#039;112&amp;#039;&amp;#039;&amp;#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &amp;quot;Phase Transition in Elastic Disks&amp;quot;, Physical Review &amp;#039;&amp;#039;&amp;#039;127&amp;#039;&amp;#039;&amp;#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &amp;quot;Large-scale simulations of the two-dimensional melting of hard disks&amp;quot;, Physical Review E &amp;#039;&amp;#039;&amp;#039;73&amp;#039;&amp;#039;&amp;#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\eta &amp;lt; 0.699)&amp;lt;/math&amp;gt;, a  hexatic phase, and a solid phase &amp;lt;math&amp;gt;(\eta &amp;gt; 0.723)&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &amp;quot;Über einen geometrischen Satz.&amp;quot; Mathematische Zeitschrift &amp;#039;&amp;#039;&amp;#039;46&amp;#039;&amp;#039;&amp;#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &amp;quot;Prediction of a structural transition in the hard disk fluid&amp;quot;, Journal of Chemical Physics &amp;#039;&amp;#039;&amp;#039;133&amp;#039;&amp;#039;&amp;#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &amp;quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&amp;quot;, Journal of Physical Chemistry B &amp;#039;&amp;#039;&amp;#039;112&amp;#039;&amp;#039;&amp;#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/del&gt;&lt;/div&gt;&lt;/td&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-added&quot;&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;:&amp;#039;&amp;#039;Main article: [[Equations of state for hard disks]]&amp;#039;&amp;#039;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;:&amp;#039;&amp;#039;Main article: [[Equations of state for hard disks]]&amp;#039;&amp;#039;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Virial coefficients==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Virial coefficients==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;:&amp;#039;&amp;#039;Main article: [[Hard sphere: virial coefficients]]&amp;#039;&amp;#039;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;:&amp;#039;&amp;#039;Main article: [[Hard sphere: virial coefficients]]&amp;#039;&amp;#039;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;==See also==&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;*[[Binary hard-disk mixtures]]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==References==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==References==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;references/&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&amp;lt;references/&amp;gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Carl McBride</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=12293&amp;oldid=prev</id>
		<title>Carl McBride: /* References */  Added a recent publication</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=12293&amp;oldid=prev"/>
		<updated>2012-02-23T11:44:38Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;References: &lt;/span&gt;  Added a recent publication&lt;/span&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 13:44, 23 February 2012&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l22&quot;&gt;Line 22:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 22:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;*[http://dx.doi.org/10.1103/PhysRevB.30.2755     Katherine J. Strandburg, John A. Zollweg, and G. V. Chester &amp;quot;Bond-angular order in two-dimensional Lennard-Jones and hard-disk systems&amp;quot;, Physical Review B &amp;#039;&amp;#039;&amp;#039;30&amp;#039;&amp;#039;&amp;#039; pp. 2755 - 2759 (1984)]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;*[http://dx.doi.org/10.1103/PhysRevB.30.2755     Katherine J. Strandburg, John A. Zollweg, and G. V. Chester &amp;quot;Bond-angular order in two-dimensional Lennard-Jones and hard-disk systems&amp;quot;, Physical Review B &amp;#039;&amp;#039;&amp;#039;30&amp;#039;&amp;#039;&amp;#039; pp. 2755 - 2759 (1984)]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;*[http://dx.doi.org/10.1007/s00222-003-0304-9 Nándor Simányi &amp;quot;Proof of the Boltzmann-Sinai ergodic hypothesis for typical hard disk systems&amp;quot;, Inventiones Mathematicae  &amp;#039;&amp;#039;&amp;#039;154&amp;#039;&amp;#039;&amp;#039; pp. 123-178 (2003)]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;*[http://dx.doi.org/10.1007/s00222-003-0304-9 Nándor Simányi &amp;quot;Proof of the Boltzmann-Sinai ergodic hypothesis for typical hard disk systems&amp;quot;, Inventiones Mathematicae  &amp;#039;&amp;#039;&amp;#039;154&amp;#039;&amp;#039;&amp;#039; pp. 123-178 (2003)]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;*[http://dx.doi.org/10.1063/1.3687921 Roland Roth, Klaus Mecke, and Martin Oettel &quot;Communication: Fundamental measure theory for hard disks: Fluid and solid&quot;, Journal of Chemical Physics &#039;&#039;&#039;136&#039;&#039;&#039; 081101 (2012)]&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==External links==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==External links==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;*[http://www.smac.lps.ens.fr/index.php/Programs_Chapter_2:_Hard_disks_and_spheres Hard disks and spheres] computer code on SMAC-wiki.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;*[http://www.smac.lps.ens.fr/index.php/Programs_Chapter_2:_Hard_disks_and_spheres Hard disks and spheres] computer code on SMAC-wiki.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category: Models]]&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;[[Category: Models]]&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Carl McBride</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=11879&amp;oldid=prev</id>
		<title>Carl McBride: /* Phase transitions */  Added classic reference</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=11879&amp;oldid=prev"/>
		<updated>2011-10-19T13:54:41Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Phase transitions: &lt;/span&gt;  Added classic reference&lt;/span&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 15:54, 19 October 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l10&quot;&gt;Line 10:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 10:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\eta &amp;lt; 0.699)&amp;lt;/math&amp;gt;, a  hexatic phase, and a solid phase &amp;lt;math&amp;gt;(\eta &amp;gt; 0.723)&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&quot;, Journal of Physical Chemistry B &#039;&#039;&#039;112&#039;&#039;&#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;ever since the early work of Alder and Wainwright &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRev.127.359 B. J. Alder and T. E. Wainwright &quot;Phase Transition in Elastic Disks&quot;, Physical Review &#039;&#039;&#039;127&#039;&#039;&#039; pp. 359-361 (1962)]&amp;lt;/ref&amp;gt;&lt;/ins&gt;. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\eta &amp;lt; 0.699)&amp;lt;/math&amp;gt;, a  hexatic phase, and a solid phase &amp;lt;math&amp;gt;(\eta &amp;gt; 0.723)&amp;lt;/math&amp;gt; (the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) . Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&quot;, Journal of Physical Chemistry B &#039;&#039;&#039;112&#039;&#039;&#039; pp. 16059-16069 (2008)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Carl McBride</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=11878&amp;oldid=prev</id>
		<title>Carl McBride: /* Phase transitions */  Added another reference</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=11878&amp;oldid=prev"/>
		<updated>2011-10-19T13:50:19Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Phase transitions: &lt;/span&gt;  Added another reference&lt;/span&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
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				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 15:50, 19 October 2011&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l10&quot;&gt;Line 10:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 10:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;rho \leq &lt;/del&gt;0.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;890&lt;/del&gt;)&amp;lt;/math&amp;gt; hexatic &amp;lt;math&amp;gt;(\&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;rho &lt;/del&gt;&amp;gt; 0.&lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;920&lt;/del&gt;)&amp;lt;/math&amp;gt; &lt;del style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;solid&lt;/del&gt;. Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;eta &amp;lt; &lt;/ins&gt;0.&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;699&lt;/ins&gt;)&amp;lt;/math&amp;gt;&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;, a  &lt;/ins&gt;hexatic &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;phase, and a solid phase &lt;/ins&gt;&amp;lt;math&amp;gt;(\&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;eta &lt;/ins&gt;&amp;gt; 0.&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;723&lt;/ins&gt;)&amp;lt;/math&amp;gt; &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;(the maximum possible packing fraction is given by &amp;lt;math&amp;gt;\eta = \pi / \sqrt{12} \approx 0.906899...&amp;lt;/math&amp;gt; &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1007/BF01181430 L. Fejes Tóth &quot;Über einen geometrischen Satz.&quot; Mathematische Zeitschrift &#039;&#039;&#039;46&#039;&#039;&#039; pp. 83-85 (1940)]&amp;lt;/ref&amp;gt;) &lt;/ins&gt;. Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010&lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;)]&amp;lt;/ref&amp;gt; and by studying tessellations (the hexatic region: &amp;lt;math&amp;gt;0.680 &amp;lt; \eta &amp;lt; 0.729&amp;lt;/math&amp;gt;) &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1021/jp806287e John J. Kozak, Jack Brzezinski and Stuart A. Rice &quot;A Conjecture Concerning the Symmetries of Planar Nets and the Hard disk Freezing Transition&quot;, Journal of Physical Chemistry B &#039;&#039;&#039;112&#039;&#039;&#039; pp. 16059-16069 (2008&lt;/ins&gt;)]&amp;lt;/ref&amp;gt;.&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;br&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Carl McBride</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=10743&amp;oldid=prev</id>
		<title>Carl McBride: /* Phase transitions */  Added a recent publication</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=10743&amp;oldid=prev"/>
		<updated>2010-10-26T10:00:23Z</updated>

		<summary type="html">&lt;p&gt;&lt;span dir=&quot;auto&quot;&gt;&lt;span class=&quot;autocomment&quot;&gt;Phase transitions: &lt;/span&gt;  Added a recent publication&lt;/span&gt;&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;col class=&quot;diff-marker&quot; /&gt;
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				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;2&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 12:00, 26 October 2010&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot; id=&quot;mw-diff-left-l10&quot;&gt;Line 10:&lt;/td&gt;
&lt;td colspan=&quot;2&quot; class=&quot;diff-lineno&quot;&gt;Line 10:&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;where &amp;lt;math&amp;gt; \Phi_{12}\left(r \right) &amp;lt;/math&amp;gt; is the [[intermolecular pair potential]] between two disks at a distance &amp;lt;math&amp;gt;r := |\mathbf{r}_1 - \mathbf{r}_2|&amp;lt;/math&amp;gt;, and &amp;lt;math&amp;gt; \sigma &amp;lt;/math&amp;gt; is the diameter of the disk. This page treats hard disks in a two-dimensional space, for three dimensions see the page [[hard disks in a three dimensional space]].&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Phase transitions==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;−&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #ffe49c; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\rho \leq 0.890)&amp;lt;/math&amp;gt; hexatic &amp;lt;math&amp;gt;(\rho &amp;gt; 0.920)&amp;lt;/math&amp;gt; solid.&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;Despite the apparent simplicity of this model/system, the phase behaviour and the nature of the phase transitions remains an area of active study. In a recent publication by Mak &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1103/PhysRevE.73.065104 C. H. Mak &quot;Large-scale simulations of the two-dimensional melting of hard disks&quot;, Physical Review E &#039;&#039;&#039;73&#039;&#039;&#039; 065104(R) (2006)]&amp;lt;/ref&amp;gt;  using over 4 million particles &amp;lt;math&amp;gt;(2048^2)&amp;lt;/math&amp;gt; one appears to have the phase diagram isotropic &amp;lt;math&amp;gt;(\rho \leq 0.890)&amp;lt;/math&amp;gt; hexatic &amp;lt;math&amp;gt;(\rho &amp;gt; 0.920)&amp;lt;/math&amp;gt; solid. &lt;ins style=&quot;font-weight: bold; text-decoration: none;&quot;&gt;Similar results have been found using the [[BBGKY hierarchy]] &amp;lt;ref&amp;gt;[http://dx.doi.org/10.1063/1.3491039  Jarosław Piasecki, Piotr Szymczak, and John J. Kozak &quot;Prediction of a structural transition in the hard disk fluid&quot;, Journal of Chemical Physics &#039;&#039;&#039;133&#039;&#039;&#039; 164507 (2010)]&amp;lt;/ref&amp;gt;.&lt;/ins&gt;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-side-deleted&quot;&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot; data-marker=&quot;+&quot;&gt;&lt;/td&gt;&lt;td style=&quot;color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #a3d3ff; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt; &lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;==Equations of state==&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;tr&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;:&amp;#039;&amp;#039;Main article: [[Equations of state for hard disks]]&amp;#039;&amp;#039;&lt;/div&gt;&lt;/td&gt;&lt;td class=&quot;diff-marker&quot;&gt;&lt;/td&gt;&lt;td style=&quot;background-color: #f8f9fa; color: #202122; font-size: 88%; border-style: solid; border-width: 1px 1px 1px 4px; border-radius: 0.33em; border-color: #eaecf0; vertical-align: top; white-space: pre-wrap;&quot;&gt;&lt;div&gt;:&amp;#039;&amp;#039;Main article: [[Equations of state for hard disks]]&amp;#039;&amp;#039;&lt;/div&gt;&lt;/td&gt;&lt;/tr&gt;
&lt;/table&gt;</summary>
		<author><name>Carl McBride</name></author>
	</entry>
	<entry>
		<id>http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=10111&amp;oldid=prev</id>
		<title>Carl McBride: Hard disks moved to Hard disk model: Better title.</title>
		<link rel="alternate" type="text/html" href="http://www.sklogwiki.org/SklogWiki/index.php?title=Hard_disk_model&amp;diff=10111&amp;oldid=prev"/>
		<updated>2010-04-07T09:52:21Z</updated>

		<summary type="html">&lt;p&gt;&lt;a href=&quot;/SklogWiki/index.php/Hard_disks&quot; class=&quot;mw-redirect&quot; title=&quot;Hard disks&quot;&gt;Hard disks&lt;/a&gt; moved to &lt;a href=&quot;/SklogWiki/index.php/Hard_disk_model&quot; title=&quot;Hard disk model&quot;&gt;Hard disk model&lt;/a&gt;: Better title.&lt;/p&gt;
&lt;table style=&quot;background-color: #fff; color: #202122;&quot; data-mw=&quot;interface&quot;&gt;
				&lt;tr class=&quot;diff-title&quot; lang=&quot;en&quot;&gt;
				&lt;td colspan=&quot;1&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;← Older revision&lt;/td&gt;
				&lt;td colspan=&quot;1&quot; style=&quot;background-color: #fff; color: #202122; text-align: center;&quot;&gt;Revision as of 11:52, 7 April 2010&lt;/td&gt;
				&lt;/tr&gt;&lt;tr&gt;&lt;td colspan=&quot;2&quot; class=&quot;diff-notice&quot; lang=&quot;en&quot;&gt;&lt;div class=&quot;mw-diff-empty&quot;&gt;(No difference)&lt;/div&gt;
&lt;/td&gt;&lt;/tr&gt;&lt;/table&gt;</summary>
		<author><name>Carl McBride</name></author>
	</entry>
</feed>