[gmx-users] Re: gmx-users digest, Vol 1 #653 - 10 msgs

[Erik Lindahl]

>
> Here when I want to simulate molecules in water, using PME, I found 
> that
> all the system including waters, solutes have translational motions
> building up. The system is moving faster and faster.

That is a well-known artefact in all types of MD simulation; it comes 
from the small rounding errors in the forces building up an 
acceleration.

By default, Gromacs (as most other programs) removes this motion every 
step, so check the value of nstcomm you're using in the mdp file!

(you might have disabled it by mistake).

Cheers,

Erik