If a parmed.Structure has multiple dihedral potentials for a single set of atoms, then this information is lost in the conversion to the gmso.Topology.

I have put together a gist with a simplified example:

import parmed
from gmso.external import from_parmed

pmd = parmed.load_file("emim_fake.top", xyz="emim.gro")
top = from_parmed(pmd)

print(top.dihedral_types)
print(pmd.dihedrals)