With these two clusters, using a similar approach to our previous work, we determined the space groups of the corresponding crystals structures. Details of this process can be found in Section S3.1. For the cluster where the cages were aligned between the layers, the space group was found to be P 3, matching the experimental structure of B11 reported in the literature (CCDC code PIFVAE ). For the cluster where the cages were antialigned between the layers, the space group was P 3c1, which has not been reported experimentally. With these two structures, we sought to determine which one was more energetically stable.