[gmx-users] new atom

[Malihe Hasanzadeh]

Hi
I want to do a Pr-Ligand MD simulations by gromacs 5.0.5. My protein has
two Ni ions. I added parameters of Ni to ffnonbonded.itp , atomtypes.atp
and ions.itp. I also added "Ni Ion" to residuetypes.dat. But when I run
pdb2gmx, gives this :Warning: Starting residue NI571 in chain not
identified as Protein/RNA/DNA".
Could you please help me what id my mistake?
Thanks