Sensitivity of morphology prediction to the force field: Paracetamol as an example

Abstract

The growth morphology of paracetamol is known to show a strong supersaturation dependence. Most morphology prediction methods, like the attachment energy method, cannot include this dependence in their prediction. Monte Carlo simulations are able to use the supersaturation as an input parameter and can also include the growth mechanism. This makes the Monte Carlo technique a powerful tool to study the growth of organic crystals. Some studies in the literature show that the attachment energy method is only weakly influenced by the force field used to calculate the attachment energies. The present paper presents the sensitivity of the Monte Carlo simulation results to the force field and charge set using paracetamol as a case study. The force field and atomic point charges are found to influence the results to a large extent. This is due to subtle differences in step energies that determine the growth rates of the crystal faces.