The rhodium and linker atom charges for the analog models, reported in Figures and in the SI, respectively, were computed to determine the electronic impact of the phenyl groups. The rhodium charges become slightly more positive compared to the full complexes; however, the largest increase is only 0.07 a.u. and the charge remains unaffected by the bite angle. The average phosphorus charge becomes 0.5 -0.6 a.u. more negative, bringing the charges closer to those seen in the minimal models. Phenyl groups are inductively withdrawing, Figure : Reactant rhodium charges of all reactions in the hydrogen evolution cycle for the pm, pb, px, and mae complexes. The transparent lines are the P(c 4 ) minimal model scans for each reaction. so removing them allows the phosphorus linker atoms to retain more electron density. While the linker atom charge changes fairly significantly, the limited effect on the rhodium charge suggests the effect of the phenyls is mostly steric.