[CPMD-list] Constraining Center of Mass

[luca]

Hi,
     I need to constraint the CofM in a MD simulation. These because,
with nose thermostats for ions and wavefunctions swithched on, for a
system I am studying there are huge drifts in the CofMass, that is
absorbing a consistent amount of the total kinetik energy, so that the
real temperature of the system is far from the target. It seems that the
keyword FIX COM (reading the code) does work only during a geometry
optimization, and not the MD run. Is that true (I am using version
3.4.3)?
Is there a way to constraint the center of mass, better than restart
every now and then to impose a new set of velocities?

Regards,
Luca Ghiringhelli.