Another feature of LigandDiff is that it is scaffold-based, i.e., it only diffuses or denoises one ligand while other ligands as well as the central metal are fixed at each step. In drug discovery such "scaffold modeling" is widely used where a large portion of the molecule is kept fixed while the remaining parts of the molecule are modified. Keeping the main scaffold structure, while modifying small functional groups, allows for accurate and quick design of new drugs with desirable properties. Generative models can further speed up such targeted exploration of the chemical space due to its powerful flexibility with little or no human intervention. In addition, the generation of one new ligand is similar to ligand substitution which is a useful tool for new material discovery in organometallic complexes. Overall, LigandDiff can be used to investigate the structure-activity relationship (SAR) in the area of metal-ligand interactions. For example, Ferrocene (Fc), a 'sandwich' organometallic complex, has two stable cyclopentadienyl groups which can be easily redesigned by either replacing the whole group with different organic groups or simply attaching extra functional groups to the five-membered rings, leading to a large variety of derivatives. Indeed, Fc analogues have shown potential as drug candidates against malaria as well as cancer and each modified cyclopentadienyl moiety has specific mechanisms by which they interact with biomolecules, which improves the overall therapeutic efficacy. We anticipate that LigandDiff has the potential to accelerate the process of lead optimization for this and other classes of organometallic compounds.