ERROR 1 [file lig.prm, line 4]: Unknown bond_atomtype CG2R51

User discussions
1

error while adding ions
used charmm36-july2022 lig.str created using CGenFF and cgenff_charmm2gmx_py3_nx2.py used to create .prm and other files
Unknown bond_atomtype CG2R51
what to do plz help

2

CG2R51 is a core CGenFF atom type and comes from the CHARMM36 force field distribution. Are you trying to mix and match force fields? A CGenFF topology must be used with the CHARMM36 force field, nothing else.

3

yes i used CGenFF topology file only. i am using gromacs 2020.1, is it the reason for the error?

4

I can’t tell you anything productive without seeing all your files (system topology, ligand topology and .prm file).