As a first pass for data generation, candidate structures are obtained from two sources. Firstly, structures are taken from the parameter fitting work of Gatsiou et al. , with the omission of structures containing linear molecules including acetylene (ACETYL05), cyanogen (CYNGEN), and dicyanoacetylene (DCYANM), as their effective treatment would introduce additional complexities in the structure optimisation code. The primary reference data set is then supplemented with a large number of additional structures taken from the CSD to extend the size of the existing dataset and develop new datasets for the fitting of additional atom-atom interactions. To fit many of the interactions commonly present in organic compounds, we construct reference datasets with molecules containing carbon, hydrogen, nitrogen, oxygen, fluorine, chlorine, and sulphur. Only structures with no known disorder and with all atom positions recorded in the crystallographic file are added to the reference datasets. No constraints are enforced as to the experimental methods used, the discrepancy factors in structure resolution, or the temperature at which the crystal structures were resolved. The use of DFT-D calculations to optimise the geometry of these structure should eliminate any small discrepancies arising from measurement errors or temperature effects. In general, crystals comprising few small rigid molecules in the unit cell are preferentially selected to reduce the cost of the DFT-D calculations. This may lead to some biases in the reference datasets toward conjugated or aromatic systems which occur more commonly. Systems with several polymorphic structures matching the above criteria are also preferentially selected to allow the assessment of the model predictions of relative energy differences between polymorphs. Only structures for which the final DFT-D optimised geometry produce a good match with the experimental geometry are included in the reference set. This excludes the structure of formaldehyde (KEMZIL), among others, due to large deviations between the DFT-D optimised and experimental structure.