[gmx-users] Defining a limited space for the movement of Ion

[Alexander Alexander]

Dear Gromacs user,

I have defined a "molecule = A" and a single ion together as
"[moleculetype] = A + Ion" in my simulations. But, I get some problem when
Ion goes so far away from the molecule A, because physically I would have a
separated molecules defined as [moleculetype], so, I want somehow keep the
Ion close to the molecule in simulation, I mean just in physically
meaningful-limited sphere around the the molecule.
Would you please let me know how I can do that?

Thanks,
Regards,
Alex