During crystallisation, molecules are not restricted to their lowest energy conformer, and the balance of inter-and intramolecular interactions can sometimes lead to higher energy conformers. We quantify this with ∆E con f , the difference in energy between the conformer that relates to the crystalline molecular geometry and the global minimum energy conformer found by the conformational search process (see Fig. ). The distribution of conformational energies of guest molecules in CS structures, and comparison to those in pure and cocrystal structures, is detailed in Fig. .