[gmx-users] COM motion removal problem

[Christoph Freudenberger]

Erik Lindahl wrote:
> It means that we remove the center-of-mass motion every "nstcomm" steps. 
> So, if you set it to 10000 you could get quite a buildup of kinetic 
> energy during the first 9999 steps, and then it is reset back.

right, and if it is removed temperature will drop "a few" kelvins. 
that's how i would interpret filip's results.

> In most cases I'd recommend to remove it every step, i.e. setting 
> nstcomm to 1.
I already guessed so, because if you don't set any comm-parameters
grompp will automaticaly set comm_mode=linear and nstcomm=1.
but why than the "should only be used for vacuum simulations"-remark?

regards
-- 
Christoph Freudenberger
Abt. Organische Chemie I AK Siehl - Uni Ulm -Tel: ++49-731-502-2785