[gmx-users] Regarding No more replaceable solvent!

[Alex]

How about you actually open your 'glywi.gro' prior to adding more ions 
and count the number of water molecules, and then compare it with the 
number of ions you want to add? With concentration known and the 
knowledge of your box volume, this comparison shouldn't be a problem.

Alex


On 2/18/2018 11:14 PM, Dilip H N wrote:
> Hello,
> I added 10 Na+ and Cl- ions to the aminoacid-water system containing 512
> molecules through the command
> gmx genion -s em.tpr -o abc.gro -p topol.top -pname NA -nname CL -np 10 -nn
> 10
>
> but now, i want to increase the concentration, so i want to add 45 Na+ and
> Cl- ions (from calculation, the concentration for 45 ions is 5M...), but
> when i give the commands:
> gmx genion -s em.tpr -o glywi.gro -p topol.top -pname NA -nname CL -np 45
> -nn 45
>                                                       (or)
> gmx genion -s em.tpr -o glywi.gro -p topol.top -pname NA -nname CL -conc 5
>
> I am getting the error as:
>
> No more replaceable solvent!
>
> So, Is there any limit here..?? The maximum concentration that i can get is
> 2M (through -conc 2 command), and after that, if i change from -conc2 to
> -conc3 etc., i am getting the same error as "No more replaceable solvent!".
>
> Any suggestions are appreciated...
>
> Thank you
>
>