The study of framework topology has historically been extensively applied to zeolites . One reason is that the structure of zeolites, made only from tetrahedral (T = Si, Al, . . . ) atoms bridged by T-O-T linkages, is simple enough to show an almost one-to-one correspondence between each framework and its underlying net. Using this fact, large databases of hypothetical zeolites have been devised: the core idea consists in embedding 4-connected nets in real space, either by enumeration of the nets or by Monte-Carlo sampling of vertex positions . The vertices correspond to Si atoms while O atoms are placed along the edges. Each obtained structure is subsequently refined by minimizing its energy through molecular dynamics and with simulated annealing.