[gmx-users] pdb2gmx residue error

[Elias Ahadi]

Hi,

I am trying to do a simple NaCl solvation and MD run using GROMACS. I have 4 atoms in my (.xyz) file for the 2 Na's and 2 Cl's. I convert the (.xyz) to (.pdb) using babel. Afterwards, I try to generate the topology file using pdb2gmx program and it generates an error.  I am using the 43a1 force field.

FATAL ERROR: Residue "LIG" not found in residue topology database.

Has anyone come across this problem before?

Thanks