(CPP, see the upper left box in Figure ). The authors have also identified that beyond 300 s coalescence process starts (although individual particles retain their individual size and shape), indicating that particle growth took place during the first minutes of synthesis. From the thermodynamic point of view, classical growth mechanisms proceed to yield morphologies that minimize the total Gibbs surface free energy. At the same time, a kinetic analysis would suggest that, for the growth process to take place, MOF precursors must diffuse and reach the surface of the growing crystal and form coordination bonds. Both steps (diffusion and coordination) could be the limiting step, depending on synthetic conditions. For low supersaturation regimes, i.e., low linker excess and low concentration of reactants, individual units (ZIF-8 precursors) coordinate onto energetically favorable points, in the socalled mononuclear regime (see the upper left panel in Figure ). It was proposed that the process involves partial coordination of imidazolate linkers with both CPP and solvent, during the formation of the ordered ZIF-8 structure, which ultimately stabilizes the develop-ing pore structure. This process results in the formation of particles with well-defined edges, favoring the densest (110) crystalline planes, and thus leading to the classic rhombic dodecahedron shape (see Figure for the classification of ZIF-8 particles' morphology). By increasing the concentrations or the HmIm excess, CPP were found to grow by the addition of small clusters of 1.1 nm rather than by coordination of individual precursors (see the second row in Figure ). In one of the reports in which such a mechanism is described, the authors suggested the growth to take place by a monomer addition mechanism; however, based on the classification herein employed, it corresponds rather to a polynuclear regime.