Following the above principles, we initially designed 25 complexes. This full list is reported in Section S4. For seven of of these complexes, geometry optimizations were not successful, and these complexes were subsequently discarded in this study. Among the 18 complexes included in this study are the ones shown in Figure . Following strategy (i), we included Nheterocyclic carbenes in some of the complexes (5-15, 18). Based on strategy (ii), we have tested 5-chelating ligands (4-6, 9, 14, 15) and 6-chelating ligands (all other complexes). In strategy (iii), we have used pyridine ligands (1-4, 6-8, 10) as also present in the reference complex VCl 3 (ddpd). For strategy (iv), we included anionic phenyl ligands (4, 5, 9, 12-17). Finally, in strategy (v) we varied the Cl -ligands only be NO - 2 , OH -, and CO ligands (1, 2, 6). We have kept the coordination motif of using a single tridentate ligand and three monodentate ligands for all complexes. We did not consider to replace the three small monodentate ligands with larger organic ligand, since our computational screening also involves multi-configurational calculations (see below). These calculations quickly become unfeasible when increasing the number of important frontier orbitals as is the case when introducing further extended organic ligands with high-lying π and low-lying π * orbitals.