[gmx-users] Randomly replace molecules with another molecule

[Li, Shi]

Dear Gromacs users,

I am wondering if there is a better way to randomly replace some molecules
in a system box with another type of molecule. For example, I have a system
with 1000 molecule A as the solvent and I have another molecule B as the
solute. I want to generate a series of systems with different concentration
of B. Is there some gmx command to do that?

I tried to use gmx insert-molecuels, but then I will need to first create a
series of system A in order to insert different number of B.
I don't know if gmx genion could do that or not, as I tried to use this but
I am not sure how to make the replacement with B as both of them are charge
neutral.

If you have a better solution. Please let me know! Thank you!

Shi