PySoftK the selected site on the monomer where a bond is formed. Finally, to provide a realistic initial structure, PySoftK utilizes the MMFF or UFF force-field parameterizations (as chosen with the FF parameter) as implemented in RDKit 40 in order to generate an energy minimized molecular conformation after iter_ff steps of minimisation. This process is displayed in Figure , where a single furan molecule is decorated with a placeholder atom (in this case bromine) shown in pink and extended to form a linear polymer containing five monomers. The full block of code required to generate this homopolymer is found in Listing 2.