Error running pdb2gmx

User discussions
1

GROMACS version:
GROMACS modification: Yes/No
Here post your question Fatal error:
Residue 18 named PHE of a molecule in the input file was mapped
to an entry in the topology database, but the atom CA used in
that entry is not found in the input file. Perhaps your atom
and/or residue naming needs to be fixed.

2

Your coordinate file is missing a CA atom in residue 18. You will need to reconstruct it (and any other missing atoms) before trying to process with pdb2gmx.