[gmx-users] water can't freeze

[Mark Abraham]

Wei, Xiupeng wrote:
> 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?

You need a water model that was parametrized to reproduce this 
behaviour. One can't expect 5 (or so) parameters to be capable of 
reproducing all possible properties of water - especially when you then 
use bond constraints to take several of them out of your model.

Mark