Simulations in pure water. We start our analysis with the system of MLA half-SBUs in pure water. A large cluster is formed leaving no "free" half-SBUs after approximately 70 ns. This cluster is highly ordered and forms pores. The Q interaction between half-SBUs 57 , is prevalent in this case. This conformer is entropically favored in pure solvent (water, DMF) and features p-p stacking interactions. We observe a rapid decrease in the number of clusters in the first 10 ns as almost half-SBUs are already connected with other two neighbors at this time. Also, we monitor the size of the five largest clusters. After approximately 70 ns the clusters start sintering, incorporating into the large cluster during this time. On average, each half-SBU that belongs to this cluster has three other neighboring half-SBUs. We believe that this high degree of interconnectivity is what holds this cluster intact for the rest of the simulation. The five largest clusters formed of MLA half-SBUs in pure water at the very early stages of the simulations are reported in Figure An initially equiprobable distribution of half-SBUs in water results in the formation of two relatively smaller clusters. Also, these are less ordered than in the previous case where MLB and MLC were absent. Nevertheless, the clusters present higher dimensionality than the cluster emerging from the purely MLA system. The number of clusters is gradually decreased to 2, reaching a plateau after 50 ns. One of the clusters is almost 30% larger than the other (4,380 and 3,420 atoms respectively). The average number of neighbors each half-SBU has is the largest of all cases as it plateaus to a value greater than 5 after 50 ns. Structures emerging from the simulation of assembly in pure water along with the corresponding graph representations after 20 and 100 ns of the production simulations for both "purely MLA" and equiprobable half-SBU distributions are shown in Figure . Structures and graph representations of clusters in the rest of the simulations are available in the SI, section III, Figures S12-S14, p. 10-11. Also, we calculate the distribution of cluster sizes during the simulation, and this is provided in the SI, section IV, Figure , p. 21. Furthermore, we used two clusters formed by MLA isomers in pure water after 100 ns and ran a relatively short MD simulation in vacuo. The reason is to evaluate whether clusters of higher dimension can be formed from 2D sheets, as the MIL-101 crystal is a three-dimensional network . A cluster of increased fractal dimension emerged; hence such clusters could possibly develop after longer times of self-assembly. This is further discussed in the SI, section V, p. 22. At last, we note that we shall use the following code for abbreviations throughout the text and the SI. AW: "Purely MLA in pure water", EW: "Equiprobable MLA/B/C in pure water", AWI: "Purely MLA in water with ions", EWI: "Equiprobable MLA/B/C in water with ions", AD: "Purely MLA in pure DMF", ED: "Equiprobable MLA/B/C in pure DMF", ADI: "Purely MLA in DMF with ions", EDI: "Equiprobable MLA/B/C in DMF with ions". Simulations in water with ions. The introduction of ions (Na + , F -) considerably affects the dynamics of assembly. Ions promote numerous small clusters in contrast with pure water. Crystal-like SBUs are formed in the presence of ions; 56 hence ions can help in healing defects during assembly. Also, small clusters of higher dimensions form in this case as it is desirable . At last, we observe small clusters forming during assembly under both half-SBU distributions; hence solute composition does not significantly affect the early stages of self-assembly in water with ions. In further detail, the number of clusters gradually reaches a plateau at 25 ns for MLA half-SBUs, while this happens much faster in the equiprobable half-SBU distribution. There are approximately 13 and 25 clusters in the "purely MLA" and the "equiprobable half-SBUs" cases respectively. The two largest clusters consist of 1,320 and 1,140 atoms when there are purely MLA half-SBUs and 780 and 480 atoms when there is an equiprobable distribution of half-SBUs. The average coordination of half-SBUs is similar, on average, for the largest cluster in the "purely MLA" case in presence of ions and in pure water. Nevertheless, smaller clusters (e.g., the 2 nd , 3 rd, and 4 th largest clusters) show increased coordination in presence of ions. Coordination is lower in the equiprobable half-SBU distribution in presence of ions than in pure water. Consequently, ions tend to decrease the number of half-SBU neighbors when MLB and MLC are also considered. The choice of a small concentration of ions is further validated by results obtained from a larger concentration as discussed in the SI, section VI, p. 23. Simulations in DMF. Solvent effects are investigated through simulation of the early stages of MOF self-assembly in DMF. The system, consisting of purely MLA half-SBUs, rapidly forms a large cluster where the Q configuration prevails, and linear chains are also formed. Pores form in a similar fashion as in water. In the equiprobable half-SBUs case, we see one long cluster forming in contrast with corresponding simulations in water. Consequently, pure DMF leads to a decrease in the dimensionality of the resulting structures. The number of clusters is rapidly decreased when purely MLA half-SBUs are present in DMF. Equiprobable half-SBUs lead to the formation of two large clusters (4,080 and 3,420 atoms respectively) between 30 and 50 ns. The average number of neighbors in the largest cluster plateaus at around 3 when purely MLA half-SBUs are present, while it is slightly higher when MLB and MLC are introduced. Simulations in DMF with ions. Ionic species show a completely different behavior in DMF when compared with water. The "purely MLA" system forms a large, ordered, and high-dimensional cluster compared with the one formed in absence of ions. A similar behavior is observed when ions are added when MLB, MLC are present. The time evolution of the number of clusters shows a similar trend in both half-SBU distributions resulting in 3-4 clusters after 100 ns. In "purely MLA", we observe a slightly higher degree of interconnectivity in the largest cluster as the number of neighbors is close to 3.3 against 3 in the "equiprobable half-SBUs" scenario. The evolution of the largest cluster, represented by a graph, during assembly in water, is shown in Figure . The relevant evolution during assembly in all other simulations in water and DMF, with or without ions is provided in the SI, section III, Figures S15-S21, p. 12-18. Additionally, the probability density of different cluster sizes is discussed in the SI, section IV, Figure , p. 21. Graph analysis. A graph representation of the system allows us to calculate of certain properties of the molecular network in every simulation. The equiprobable distribution of species results in higher numbers of connections per half-SBU, hence half-SBUs interact more than when MLA is the only species present. Also, the equiprobable distribution of species and the presence of ions leads to higher transitivity values; hence networks are more tightly connected as more triplets of interconnected members exist. In contrast, purely MLA systems have higher assortativity coefficients, except in the presence of ions in DMF. Consequently, MLA leads to assortative mixing where similar molecules (which have the same number of connections on average) are interconnected more. Overall, larger networks, formed when purely MLA isomers are present, feature members that connect to others with whom they share similarities (e. g. of the same number of connections), but they are not as strongly connected as smaller clusters emerging in the equiprobable distribution of species. The latter "communicate" more with others that are not similar; hence they tend to connect to molecules that share different properties in a way that can prove beneficial to heal defects in the longer term. Estimation of rates. Nucleation and growth rates are calculated for all simulations performed. Samples with purely MLA half-SBUs invariably result in faster nucleation and growth than the equiprobable distribution in pure solvent. In presence of ions in water, rates are similar for both distributions. In water, ions tend to significantly slow down nucleation. However, ions result in faster growth in the equiprobable MLA/B/C distribution and slightly slower growth for MLA half-SBUs than in pure water. MLA nucleation is much faster in water than in pure DMF, while the opposite occurs for growth. MLA/B/C also nucleate faster in pure water, while they grow slightly faster in pure DMF. Ions result in similar nucleation rates for MLA in water and DMF, while in presence of ions MLA/B/C nucleate slightly faster in DMF than in water. At last, ions induce faster growth in water than in DMF. Details on the values of nucleation and growth rates along with an example calculation are provided in the SI, section VII, Figures S27-28, Table , p. 24-25. Fractal growth process. We calculate the radii of gyration of clusters (see formed and growing in time during the simulation. We then relate these values with their corresponding size expressed in terms of number of half-SBUs. In this manner, we can calculate the fractal dimension associated with the growth process (see Figure ). In pure water, we observe that the "purely MLA" system evolves by forming two-dimensional structures as the corresponding fractal dimension is close to 2. Introduction of MLB and MLC leads to a slightly higher fractal dimension, while ions result in an overall decrease of the fractal dimension. On the other hand, in DMF, similar fractal dimension values are obtained for both solute compositions.