Figure . Effect of molecular diffusion on CO 2 capture performance ranking. Productivity (left) and energy cost (right) based on constant K eff , as well as structure-dependent K eff for representative crystallite sizes R µ = 1, 10 and 100 µm. Each curve represents a specific MOF structure and its color represents its microscopic diffusion coefficient. The higher (lower) the productivity (energy cost), the higher the performance rank of the candidate material. High diffusion coefficients are displayed with transparency for making productivity drops and energy cost increases visible in the plots. Data points for structures that fail to surpass the 95%-purity threshold are not shown.