[gmx-users] Adding Ions step

[Mahboobeh Eslami]

hi GMX users
The output of pdb2gmx told me that the protein-ligand complex has a net charge of 0(zero)
but  at the last line of my[ atoms ] directive in topol.top;"qtot 2.749e-06 ."  be  read .


1)What does this mean?

2) if my system has a net charge of 0(zero),must iadd ions to my system for neutralize?