[gmx-users] About center of mass removal

[rama david]

Hi Gromacs Specialist,
                 I want to study How the protein interact
with each other ??
  I run one simulation with  following MDP file option ..
comm_mode               = Linear                ; remove center of mass
translation
nstcomm                 = 1                     ; [steps] frequency of mass
motion removal
comm_grps               = Protein Non-Protein   ; group(s) for center of
mass motion removal


Now I decided to remove the center of mass
with following option .........
comm_mode               = None                  ; remove center of mass
translation
nstcomm                 =                       ; [steps] frequency of mass
motion removal
comm_grps               =                       ; group(s) for center of
mass motion removal

I got the following warning at the  command grompp...

 WARNING 1 [file md.mdp]:
  You are not using center of mass motion removal (mdp option comm-mode),
  numerical rounding errors can lead to build up of kinetic energy of the
  center of mass

I run with maxwarn 1 , Is I am right??

What Is  reason for above error??
Thank you in Advance

With Best Regards
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://maillist.sys.kth.se/pipermail/gromacs.org_gmx-users/attachments/20120324/04de654f/attachment.html>