A summary of the primary reference datasets is given in Table . In total, the datasets contain 445 structures which can be broadly split into 313 non-hydrogen bonding (RS1-RS23) and 132 hydrogen bonding structures (RS24-RS34, indicated by the presence of either O-H or N-H bonds). Structures are selected to contain diverse chemical environments with close contacts present for each atom-atom interaction with the exception of sulphur-chlorine interactions which are absent from the reference datasets.