Sensitivity of
Morphology Prediction to the Force Field: Paracetamol as an Example
H. M. Cuppen, G. M. Day, P. Verwer, and H. Meekes
Crystal Growth & Design, 4 (6)2004, 1341 -1349,
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.