[gmx-users] How do gromacs remove center of mass of a group?

[Mark Abraham]

zcwang wrote:
> Hi all
> I would like to know how gromacs remove center of mass motion?

The COM velocity is the rate of change of the position of the COM, i.e. 
the mass-weighted average velocity of the particles. If you subtract 
that from each particle velocity, the COM velocity becomes zero. 
Likewise for angular motion, if applicable.

> I thought it still allowed center of mass motion, but just did a
> transformation of the coordinates at a certain frequency.

I've never heard of GROMACS doing anything like that for this purpose.

> It's just like looking at the system in a noninertial system attached to
> the COM of the group.
> Is that right?

I don't know what you mean.

Mark