[gmx-users] Soft shpere

[Martin Rex]

Hi gmx-users,

i`d like to simulate a nanometer sized soft sphere solvated in 
SPC/E-water. The solute is intended to interact with the OW atoms of 
the SPC/E-water via the 
following soft potential: V(r) = V_0*(r-r_0)^-12, where r_0 corresponds 
to the radius of the sphere. If I understand it 
correctly I can apply my own force field to the simulation, but I think it 
will also influence the LY-interaction of the OW atoms. My question is if 
I can simulate this set up with gromacs without editing the soucre code 
and if so, how?

Thanx a lot
Martin