The atom environment datasets that are generated in this way are summarised in Table . The first few atom environment groups (AE1-AE6) are defined quite loosely, in many cases encompassing all definitions for a given element. This 'shotgun' approach is initially attempted in order to more quickly fill large voids in the atomic environment matrix. Thereafter, we narrow our search to more specific atom pairs. Intuitively, the atomic environments most sparsely populated in the primary datasets are those involving sulphurs and the halogens since these elements are less common in the CSD. Additionally, since the primary datasets have a greater proportion of structures that are non-hydrogen bonding, the atom environment datasets place more focus on hydrogen bonding structures containing hydrogens bonded to either oxygen or nitrogen. Both of these trends are self-evident from the selection of the target environments used in AE7-AE18. Crucially, the sulphur-chlorine interaction which was completely A compiled list of all structures included in the reference datasets (primary and atom environment) can be found as additional information in our Zenodo database (doi: 10.5281/zenodo.7813566). This includes all data regarding their optimal intermolecular and lattice energies, the geometric deviations between the optimised DFT-D structures and experimental structures, and also the .res files for the DFT-D optimised crystal structures.