[gmx-users] water can't freeze

[Vasilii Artyukhov]

Dear Xiupeng,

What you're seeing is the difference between freezing water and overcooling it.
If you want your water to crystallize, you'll actually have to make it -
e.g., by putting it in contact with ice. Normally, pure water doesn't freeze
on its own, you can easily verify this experimentally at home :)

Best regards,
Vasilii

2008/4/19, Wei, Xiupeng <xiupeng-wei at uiowa.edu>:
>
> Hi gmx users,
>          I'm a new Gromacs user. Till now, I can get pretty good
> simulation of ice melting to water, but why can't I simulate water freezing
> to ice?
>          The .top and .gro files used for water freezing simulation are
> generated by ice melting to 310K. I changed the temperature in .mdp file to
> 230K, but after mdrun, the water was still water, it can't freeze?
>          How can I get water freezing to ice?
>         I paste mdp for your reference.
>         Thanks.
>
> best,
> xiupeng
>
>
> title                    = icing at 230 K with cuffoff
> cpp                      = /lib/cpp
> integrator               = md
> ;Time step
> dt                       = 0.002
> nsteps                   = 100000
> ;Output control
> nstxout                  = 100000
> nstvout                  = 100000
> nstlog                   = 100
> nstenergy                = 100
> nstxtcout                = 100
> ;Neigbour searching
> nstlist                  = 10
> ns_type                  = grid
> rlist                    = 0.8
> ;Non bonded interaction
> coulombtype              = pme
> optimize_fft             = yes
> fourierspacing           = 0.2
> pme-order                = 6
> ewald-rtol               = 1e-05
> rcoulomb                 = 0.8
> vdw-type                 = Cut-off
> rvdw                     = 0.8
> DispCorr                 = EnerPres
> ;Temperature coupling
> tcoupl                   = berendsen
> tc-grps                  = System
> tau_t                    = 0.1
> ref_t                    = 230
> ;Pressure coupling
> pcoupl                   = berendsen
> pcoupltype               = isotropic
> tau_p                    = 1.0
> compressibility          = 5e-5
> ref_p                    = 1.0
>
> gen_temp                 = 230.0
> constraints              = all-bonds
> ; generate velocities
> gen_vel                  = yes
> gen_seed                 = 173529
>
>
> _______________________________________________
> gmx-users mailing list    gmx-users at gromacs.org
> http://www.gromacs.org/mailman/listinfo/gmx-users
> Please search the archive at http://www.gromacs.org/search before posting!
> Please don't post (un)subscribe requests to the list. Use the
> www interface or send it to gmx-users-request at gromacs.org.
> Can't post? Read http://www.gromacs.org/mailing_lists/users.php
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://maillist.sys.kth.se/pipermail/gromacs.org_gmx-users/attachments/20080419/bf420e6f/attachment.html>