[gmx-users] deleting duplicate atoms

[Lakshmi Padmavathi]

Dear gromacs users,

      i am using a protein with special residues. that special residue 
contained one N=O group, in ring. i would like to use ffG43b1 because i want 
to make stimulation in vaccum.

but the pdb2gmx program says that

deleting duplicating atoms    O

after that again it said O1 not found ( atom name O1).

for my protein this oxygen(N=O) is very important.

I hope any of you could help for me.

thank you very much.

sincerely,