[gmx-users] constraining com of a group

[K.A. Feenstra]

David L. Bostick wrote:
> Hello list,
> 
> Is there a way to constrain (freeze) the center of mass of a group of
> atoms to a single position during MD?  If not, is there a way to restrain
> it?

The 'pull' option pulls on the com of a group of atoms, so it should
be possible to use it to restrain the com. I don't know how, however.

The 'freeze groups' option removes all motion of *each* of the atoms,
which then probably is not what you'd want.


-- 
Groetjes,

Anton
  ________ ___________________________________________________________
|        | Anton Feenstra                                            |
| .      | Dept. of Pharmacochemistry - Vrije Universiteit Amsterdam |
| |----  | De Boelelaan 1083 - 1081 HV Amsterdam - The Netherlands   |
| |----  | Tel: +31 20 44 47608 - Fax: +31 20 44 47610               |
| ' __   | Feenstra at chem.vu.nl - http://www.chem.vu.nl/afdelingen/FAR|
|  /  \  |-----------------------------------------------------------|
| (    ) | Dept. of Biophysical Chemistry - University of Groningen  |
|  \__/  | Nijenborgh 4 - 9747 AG Groningen - The Netherlands        |
|   __   | Tel +31 50 363 4327 - Fax +31 50 363 4800                 |
|  /  \  | K.A.Feenstra at chem.rug.nl - http://md.chem.rug.nl/~anton   |
| (    ) |-----------------------------------------------------------|
|  \__/  | "If You See Me Getting High, Knock Me Down"               |
|        | (Red Hot Chili Peppers)                                   |
|________|___________________________________________________________|