Thermodynamics and electronic structure evolution from single-H ₂ adsorption to stepwise hydrogen loading of Fe metalloporphyrin

maps confirm a shift from localized attractive contributions at low coverage to dispersive confinement and steric crowding at high coverage. Together, these results separate capacity from usability in a chemically transparent adsorbent and provide a transferable design rule for computational materials discovery: high uptake must be accompanied by the multiplication of intermediate-strength binding motifs to move the storage manifold beyond a purely dispersion-dominated outer shell.