[gmx-users] problem with simulation of freezing of water

[Erik Marklund]

The phase transition of water from liquid to ice is very hard to observe in MD simulations. In the lab you can in fact supercool water for minutes without ice forming until you trigger the phase transition by e.g. knocking the beaker or add nucleating agents. An MD simulation takes place on timescales that are maaaaany orders of magnitude shorter, so obtaining ice in simulations when starting form a liquid system seem as likely as winning a billion dollars and getting struck by lightning at the same time.

There are water models that nucleate much more easy than in experiments, which may be useful for you.

Best,

Erik


11 nov 2012 kl. 15.53 skrev Ali Alizadeh:

> Dear All users
> 
> I  did simulation of water freezind at low temperature(260 k) so that
> i was hoped to see
> regular structure of ice,
> 
> I used OPLS-AA force field, SPC and 100ns,
> 
> But i can not see the regular structure of ice(i used vmd for
> representation of my simulation)?
> 
> In your opinion, Where did i mistake in my simulation?
> 
> Where did i mistake in my simulation?
> -- 
> Sincerely
> 
> Ali Alizadeh
> -- 
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-----------------------------------------------
Erik Marklund, PhD
Dept. of Cell and Molecular Biology, Uppsala University.
Husargatan 3, Box 596,    75124 Uppsala, Sweden
phone:    +46 18 471 6688        fax: +46 18 511 755
erikm at xray.bmc.uu.se
http://www2.icm.uu.se/molbio/elflab/index.html