The structure of doxorubicinone (EZEWOY) has unphysically high ∆E strain and ∆E con f energies. The host framework is wellresolved, however the guest model required a considerable number of restraints and constraints to impose reliable geometry and crystallographic parameters. There is a high likelihood that these have significantly distorted the molecular geometry and resulted in these artificially high calculated energies. For this reason this structure is an outlier in the group and has not been included further in this analysis. All remaining discussion includes only the remaining 16 CS structures. The distortion of any molecule away from its gas phase geometry involves an increase in the intramolecular energy ∆E strain and possibly of the conformational energy ∆E con f , if the molecule adopts a conformer other than its most favourable gas phase conformation within the CS. Firstly the total relative energy ∆E total of a molecule in a CS crystal structure from its gas phase geometry is analysed. This is calculated as the difference between the energy of the isolated molecule in the geometry from its DFT optimised crystal structure and the gas phase (global minimum) energy, according to Equation .