There is a wealth of experimental and theoretical literature exploring the fundamentals of the chemisorption process. The general understanding is that CO 2 adsorption in amine-functionalized MOFs mostly manifests in the form of insertion of CO 2 between the metal node and primary amine, with proton transfer and the formation of ammonium carbamate chains , causing step-shaped isotherms, and thus greater working capacity with smaller temperature or pressure swings. The other predominate chemistry is carbamic acid formation , assumed to be in pairs on the secondary amines. With these chemistries, the maximum theoretical capacity is 1 CO 2 molecule per diamine or 2 CO 2 molecules per tetramine. As such, an accurate prediction of amine loading (i.e., how many amines can fit in the unit cell of a MOF) allows predicting maximum sorbent capacity. A particular configuration of an amine in the pore (a so-called motif) also influences the stability, pore volume, and binding energy.