To assess their utility in establishing hydrogen storage performance, the weighted average of adsorption enthalpy and the heterogeneity parameter for the MFU-4l frameworks and selected framework materials were estimated with fit parameters for the total high-pressure H2 isotherms in a dual-site Langmuir model (Tables 6, S13, and S14). The weighted average of adsorption enthalpies for MFU-4l frameworks is -4 to -5 kJ/mol in all cases, indicating that the weak adsorption sites dominate the total uptake of H2 in the MFU-4l frameworks. In contrast, Ni2(mdobdc)-the current benchmark adsorbent for ambient-temperature H2 storage-shows a higher weighted average of adsorption enthalpy and a smaller heterogeneity parameter than Cu I M-MFU-4l-type materials and other frameworks with strong H2 binding sites. This finding indicates that a