[gmx-users] isotropic force constant?

[Qiang Zhong]

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!