We find that simple models can give qualitative agreement with the reactivity calculated for full complexes when bulky substituents are removed, allowing us to isolate the effect of individual molecular descriptors. The largest effects on reactivity are given by the choice of linker atom in the ligand, followed by its coordination. The models suggest that the L -Rh -L bite angle has a much smaller impact on the reactivity than the previous two factors. Steric effects of bulky substituents on the main ligand scaffold can also lead to large effects on the reactivity, which may be hard to fine-tune. Based on analysis of the structures and specific atomic charges, the effect on reactivity from changing the linker atom is mostly due to differences in electron-directing ability between elements, while the bite angle and coordination mainly alter the steric bulk of the complex. Therefore, we propose that functionalization of the ligand (for a given choice of linker atom) with electrondirecting groups is a better way to fine-tune the flow of electron density to and from the Rh center, rather than focusing on the bite angle. Obviously, one also needs to take into account possible steric effects of bulky substituents, as mentioned above. With these recommendations, it may be possible to develop a catalyst that is active enough to produce dihydrogen, while still being stable enough to experimentally study its intermediate structures.