By fitting the U parameter to each SBU/gas-molecule system, it is possible to align the adsorption energy of the molecule on the SBU model calculated with PBE+USBU to that of HSE06 within a maximum deviation of 0.2 eV for all systems under consideration. Deviations between PBE+USBU and HSE06 persist primarily if the adsorption energy is insensitive to the U correction or if the effect of U is to tune the adsorption in the wrong direction with respect to HSE06. The MAD of the adsorption energy of SBUs calculated with respect to HSE06 decreases from 0.15 eV with PBE to 0.02 eV when the SBU-specific U is used in a PBE+U calculation (Figure ). Even when fitting the U parameter for a group of SBUs that share the same metal/gas-molecule pair, we found that only two cases, N2 and O2 binding on Co2Cl2-BBTA, exhibit PBE+Umetal errors exceeding 0.2 eV. The MAD of the adsorption energy of SBUs calculated using PBE+Umetal with respect to HSE06 remains at 0.04 eV, which is comparable to the previous scenario where the SBU-specific U is applied, with the benefit of making the approach more general (Supporting Information Figure ). The two sets of U parameters show comparable performance even though the USBU and Umetal parameters that would be used for a MOF-adsorbate complex differ by 3.1 eV across the set of MOFs studied here. They differ because Umetal is fit to reduce errors on average across all MOFs with that metal and adsorbate, whereas USBU is fit to each SBU (Supporting Information Figure ). The small difference in performance of the two U parameter fitting approaches can be attributed to the relatively low sensitivity of the adsorption energy to changes in the U parameter. In fact, the adsorption energy of 43 of 72 cases show a deviation of less than 0.1 eV when the U parameter is varied from 0 eV to 15 eV (Supporting Information Figure ). The value of the calibrated U parameters is influenced by the sensitivity of the adsorption energies to the U parameters and by the magnitude of the original deviation between the two functionals. Both the SBU-specific and metal-specific U parameters exhibit a distribution centered around 3-4 eV (Figure ). For SBU-specific U parameters in the most extreme cases, the calibrated U parameters reach 15 eV for 9 out of 72 cases, and, in the opposite direction, the PBE results of another 10 cases already agree well with HSE06 without the need for the U parameter. The highest values of the U parameter are observed mainly for the cases of O2 and CO2 adsorption. A large U parameter is required when the adsorption energy demonstrates relatively low sensitivity to the U parameter, as is the case for CO2, or when there is a significant difference between PBE and HSE06 results, as is the case for O2 (Figure ). For example, the SBU-specific U parameter is set at 15 eV for both O2 on Ni2(OH)2-BBTA and CO2 on Fe2Cl2-BBTA. While the adsorption energy of O2 on Ni2(OH)2-BBTA exhibits a notable variation of 0.26 eV when the U parameter is varied from 0 eV to 15 eV, the adsorption energy of CO2 on Fe2Cl2-BBTA experiences a much smaller variation of 0.06 eV.