FUSE assembles crystal structures from small building blocks of atoms called submodules, derived based on chemical knowledge, each of the eight position motifs contains positions for 1 cation (the cation position can be assigned as vacant) and 0-3 anions arranged in a planar grid . When submodules are generated, the species on each specific site is randomly allocated. The submodules are grouped together to assemble single atom thick layers called modules, which are in turn stacked on top of each other to create a full crystal structure. Potential structures are then explored using a modification of a Monte Carlo search algorithm defined in the previous section (Fig. ):