Anisotropic particles with tetrahedral symmetry: Difference between revisions

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The '''phase diagram of tetrahedral''' [[patchy particles]] <ref>[http://dx.doi.org/10.1021/jp9081905 F. Romano, E. Sanz and F. Sciortino  "Role of the Range in  the Fluid−Crystal Coexistence for a Patchy Particle Model", Journal  of Physical Chemistry B '''113''' pp. 15133–15136 (2009)]</ref>
[[Image:patchy_4.png|thumb|right| Artists impression of a tetrahedral patchy particle]]
exhibits the following solid phases: [[Building up a diamond lattice |diamond crystal]] (DC),
'''Anisotropic particles with tetrahedral symmetry'''
==Kern and Frenkel model==
===Phase diagram===
The [[Phase diagrams |phase diagram]] of the tetrahedral [[Kern and Frenkel patchy model | Kern and Frenkel ]] [[patchy particles | patchy model]] exhibits the following solid phases<ref>[http://dx.doi.org/10.1021/jp9081905 Flavio Romano, Eduardo Sanz and Francesco Sciortino  "Role of the Range in  the Fluid−Crystal Coexistence for a Patchy Particle Model", Journal  of Physical Chemistry B '''113''' pp. 15133–15136 (2009)]</ref><ref>[http://dx.doi.org/10.1063/1.3393777 Flavio Romano, Eduardo Sanz and Francesco Sciortino "Phase diagram of a tetrahedral patchy particle model for different interaction ranges", Journal of Chemical Physics '''132''' 184501 (2010)]</ref>:
[[Building up a diamond lattice |diamond crystal]] (DC),
[[Building up a body centered cubic lattice | body centred cubic]] (BCC) and [[Building up a face centered cubic lattice |face centred cubic]] (FCC). The gas-liquid [[critical points | critical point]] becomes metastable with respect
[[Building up a body centered cubic lattice | body centred cubic]] (BCC) and [[Building up a face centered cubic lattice |face centred cubic]] (FCC). The gas-liquid [[critical points | critical point]] becomes metastable with respect
to the diamond crystal when the range of the interaction becomes short (roughly less than 15% of the  
to the diamond crystal when the range of the interaction becomes short (roughly less than 15% of the  
diameter).   
diameter).   


:[[Image:romanojpcb09.gif]]
:[[Image:romanojpcb09.gif]]


In contrast to isotropic models, the critical point becomes only weakly metastable  with respect to the solid as the interaction range  
In contrast to isotropic models, the critical point becomes only weakly metastable  with respect to the solid as the interaction range  
narrows (from left to right in the figure).
narrows (from left to right in the figure).
===Crystallization===
Tetrahedral Kern-Frenkel patchy particles crystallise spontaneously into open tetrahedral networks for narrow patches (solid angle < 30). The interaction range does not play an important role in crystallisation <ref>[http://dx.doi.org/10.1063/1.3578182 Flavio Romano, Eduardo Sanz, and Francesco Sciortino "Crystallization of tetrahedral patchy particles in silico", Journal of Chemical Physics '''134''' 174502 (2011)]</ref>
[[Image:fig5.jpg]]
Interaction range, <math>\delta</math>, versus patch angular width.
Diamonds correspond to crystallising and circles to glass–forming models.
The point studied in Ref. <ref>[http://dx.doi.org/10.1063/1.3578182 Zhenli Zhang, Aaron S. Keys, Ting Chen, and Sharon C. Glotzer "Self-Assembly of Patchy Particles into Diamond Structures through Molecular Mimicry", Langmuir '''21''' 11547 (2005)]</ref> is included.
When the patches in this model are made even wider (while still enforcing the limit of a single bond per patch), the diamond phase becomes metastable with respect to a liquid phase, which is stable even in the zero-temperature limit <ref>[http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys2693.html Frank Smallenburg and Francesco Sciortino "Liquids more stable than crystals in particles with limited valence and flexible bonds", Nature Physics '''9''' 554 (2013)]</ref>.
==Modulated patchy Lennard-Jones model==
The solid phases of the [[modulated patchy Lennard-Jones model]] has also been studied <ref>[http://dx.doi.org/10.1063/1.3454907  Eva G. Noya, Carlos Vega, Jonathan P. K. Doye, and Ard A. Louis "The stability of a crystal with diamond structure for patchy particles with tetrahedral symmetry", Journal of Chemical Physics '''132''' 234511 (2010)]</ref>
==Lattice model==
<ref>[http://dx.doi.org/10.1080/00268976.2010.523521 N. G. Almarza and E. G. Noya "Phase transitions of a lattice model for patchy particles with tetrahedral symmetry", Molecular Physics '''109''' pp. 65-74 (2011)]</ref>
==See also==
*[[PMW]] (primitive model for [[water]])
== References ==
== References ==
<references/>
<references/>
;Related reading
*[http://dx.doi.org/10.1063/1.3582904 G. Munaó, D. Costa, F. Sciortino, and C. Caccamo "Simulation and theory of a model for tetrahedral colloidal particles", Journal of Chemical Physics '''134''' 194502 (2011)]
*[http://dx.doi.org/10.1063/1.4840695  Ivan Saika-Voivod, Frank Smallenburg and Francesco Sciortino "Understanding tetrahedral liquids through patchy colloids", Journal of Chemical Physics '''139''' 234901 (2013)]
[[category: models]]
[[category: models]]

Latest revision as of 18:29, 28 February 2014

Artists impression of a tetrahedral patchy particle

Anisotropic particles with tetrahedral symmetry

Kern and Frenkel model[edit]

Phase diagram[edit]

The phase diagram of the tetrahedral Kern and Frenkel patchy model exhibits the following solid phases[1][2]: diamond crystal (DC), body centred cubic (BCC) and face centred cubic (FCC). The gas-liquid critical point becomes metastable with respect to the diamond crystal when the range of the interaction becomes short (roughly less than 15% of the diameter).

In contrast to isotropic models, the critical point becomes only weakly metastable with respect to the solid as the interaction range narrows (from left to right in the figure).

Crystallization[edit]

Tetrahedral Kern-Frenkel patchy particles crystallise spontaneously into open tetrahedral networks for narrow patches (solid angle < 30). The interaction range does not play an important role in crystallisation [3]

Interaction range, , versus patch angular width. Diamonds correspond to crystallising and circles to glass–forming models. The point studied in Ref. [4] is included.

When the patches in this model are made even wider (while still enforcing the limit of a single bond per patch), the diamond phase becomes metastable with respect to a liquid phase, which is stable even in the zero-temperature limit [5].

Modulated patchy Lennard-Jones model[edit]

The solid phases of the modulated patchy Lennard-Jones model has also been studied [6]

Lattice model[edit]

[7]

See also[edit]

References[edit]

Related reading