Fatal Error "Invalid dihedral type 180

GROMACS version:2023
GROMACS modification: No
Hope you are doing well. I have generated the topology of graphene oxide but after solvation I am getting the error " Invalid dihedral type 180 ". I am unable to locate this function type format error. I request you to please go through the commands and files I have attached below and help me resolve this issue.


Structure 17x17 GO built in Polypargen and submitted for OPLSAA topology parameters.
gmx editconf -f go.gro -o GO.gro (convert to correct the gro file for visualisation in vmd)
gmx editconf -f go.gro -o GO.pdb
rtp and itp obtained from TppMKTOP
included in oplsaaerg.ff
ffoplsaa.itp edited and itp files included
gmx pdb2gmx -f GO.gro -o Tpp.gro
Topology was successfully generated
gmx editconf -f Tpp.gro -d 1.0 -bt cubic -o box.gro
gmx solvate -cp box.gro -o solv.gro -p topol.top
gmx grompp -f ions.mdp -c solv.gro -p topol.top -o ions.tpr
Errors “no default bond, angle, dihedral types”
parameters taken from lack.itp and copied in Tpp.itp
gmx grompp -f ions.mdp -c solv.gro -p topol.top -o ions.tpr
Error “Invalid dihedral type 180”

This topology should not generate that error since there are no dihedrals defined. In fact, there are no atoms defined, so this is basically a useless topology. It just defines water around an “Other” type that has nothing in it.

Dear Justin,
I apologise for the incomplete upload of the topology (due to limited characters). Please check the actual topology attached below. I was unable to upload or copy paste the entire topology before.
topol.top (291.1 KB)

The error must be coming from somewhere upstream in the force field files, either through one of the macros defined or from some parameters that are referenced there.