Calculation of Attachment Energies and Relative Volume Growth Rates As an Aid to Polymorph Prediction

We calculate the morphologies of a number of the observed and hypothetical crystal structures of paracetamol, parabanic acid, and pyridine using the attachment energy model. We also estimate the relative growth volumes of the different polymorphs. This quantity is found to exhibit a large variation, which is generally well correlated with the attachment energy of the most dominant face of each polymorph, thus indicating how one face controls crystal growth. Such calculations suggest which thermodynamically feasible crystal structures could have a kinetic advantage in crystal growth. The application of the present results to polymorph prediction is discussed.