[gmx-users] isotropic force constant?

[Mark Abraham]

> Dear users:
>      I have a position restrain .mdp file need to set,I use 300K
> in which an isotropic force constant of 100kjmol-1A-1 is applied to
> all nonhydroggen protein atoms.
>
>     In my pr.mdp file which parameter I should add?
>     Thank you very much!

If you use pdb2gmx, it will generate a posre.itp file which you can modify
to do whatever you want (although I think the above might be the default).
See the manual for details on how. Then to make it work, the .mdp file
needs to have 'defines = -DPOSRE' or something similar - check manual
section 7.3.

Mark