gistfile1.txt

 def apply_multiple_forcefields(compound, residue_dict):
     """
     Applies multiple forcefields to a mb.Compound
 
     Parameters
     ----------
     compound: mb.Compound
     residue_dict: dict
         Dictionary containing residues (key) and foyer Forcefields (value) pairs
 
     Returns
     -------
     pmd.Structure: Parameterized ParmEd structure
     """
     system = pmd.Structure()
     for child in compound.children:
         if child.name in residue_dict.keys():
             system += residue_dict[child.name].apply(child)
                
     system.box = [0, 0, 0, 90, 90, 90]
     system.box[:3] = compound.periodicity
        
     return system