MC-EMMA assembles crystal structures using full modules as the fundamental building block. Once a set of modules is chosen, they are then assembled along one stacking direction. Unlike FUSE, in MC-EMMA, modules are user-defined, and are typically chosen based on fragments of known crystal structures, with each provided in the input file as either a .cif file or ase [34] Atoms object. In this work all modules are used as presented previously . Structures are then permuted in MC-EMMA using an MC search, with six possible actions used to permute the structure (Supplementary Fig. ). For clarity, these are listed as labelled within the code, and the default probability of each action being selected stated in brackets, rounded to the nearest percent: