[gmx-users] adding NaCl to water box

[Madhuri Agashe]

I am trying to add some charged ions to the water in my existing system.
My requirement is to add 7 Na and 7 Cl ions to the system. 
How do I do it?

Is it possible for me to modify .gro, .itp and .top files of my existing
water box system to replace randomly selected water molecules with Na/Cl
directly?