These atomic environments are associated with chemical groups that do not hold broad industrial and scientific interest. Consequently, their presence in the CSD, and by extension our database, is proportionately small. N 3,5,* is present only in nitro-containing compounds which are primarily used as explosives . In these energetic materials, any presence of nitrogen and oxygen is predominantly from the nitro-groups, while halogens and sulphurs are almost never featured. The spread of data related to the N 3,5,* pairwise interactions directly mirrors this. Similarly, H *,*,S is present only in thiolcontaining structures. While thiol-compounds are used in several drugs, most commonly as a chelating agent, their presence in pharmaceuticals is relatively niche . Moreover, most industrially-relevant thiol-compounds exhibit significant flexibility (branched, aliphatic compounds with many consecutive sp 3 carbons). Our attempts to screen the CSD for these structures corroborates this, with the majority of our search results being highly flexible, aliphatic structures ill-suited for our purposes. Aside from these drugs, there does not appear to be much use for organic thiol-compounds in the solid state. Beyond these systematic gaps in the data, there are some isolated groups of missing data. As mentioned before, searches involving S 1,*,* with halogens or S *,*,O were unsuccessful at generating a sufficient number of suitable candidates. Likewise, searches involving S 1,*,* and S *,*,O paired with other uncommon chemical groups like cyano-groups (C 2,*,* + N 1,3,* ) and alkyne-groups (C 2,*,* + C 2,*,* ) were also ineffective.