[gmx-users] Regarding box length variation after npt and production md run

[Alex]

Box size fluctuations during NPT are normal, while their degree may or 
may not be. In any case, your questions at the moment aren't about 
Gromacs. They suggest that you need to get a better idea on what 
barostats are, what they do, how they work, etc, etc.

Alex


On 9/24/2017 10:46 PM, Dilip H N wrote:
> Hello,
> I have ran an NPT simulation followed by NPT Production MD for different
> concentrations, and after that, if i check the final .gro files of npt.gro
> and  nptmd.gro (the production md .gro file), the box length of nptmd.gro
> is still fluctuating, for some concentrations the nptmd.gro box length is
> larger than npt.gro (which i am feeling as not correct) and in some
> concentrations the nptmd.gro box length is shorter than npt.gro.
> Still, the box length is fluctuating...
> 1] How can the box length increase after NPT simulation..??
> 2] So, how can i fix the box length, here....??
>      Do i need to run for some more no of steps or time..?? [ i ran the NPT
> simulation for 2 ns and NPT Production MD for 10 ns]
>
> Any suggestions are appreciated....
>