With the highly competitive development of chemical and pharmaceutical industries, mastering crystal growth is becoming increasingly necessary. Modern industrial manufacturers place high importance on the ability to grow crystals with a specific habit using tailored operating conditions. A detailed understanding of crystal growth is, therefore, vital for researchers in crystallography and crystallization to respond and realize this objective. Various models to predict crystal shape in the literature are reviewed here. The most commonly adopted are usually non-mechanistic and limited in their predictive power and utility, especially for products of industrial interest. Mechanistic models offer far more potential for rational crystal design, but

Recently, a general mechanistic spiral growth model, including a kink rate expression that enables crystal morphology prediction for all kinds of organic molecules (both centric and noncentric), was developed. However, we have discovered that the kink rate model for the step velocity in solution growth is inconsistent with the attachment and detachment rate expressions for noncentric growth units at kink sites, so these expressions are revisited to make them selfconsistent. Here, we derive a new expression for the kink rate for noncentrosymmetric organic molecules, which correctly accounts for the effect of solvent molecules on growth kinetics. We also generalize the kink rate model to consider other species such as additives. Using the spiral growth model with the improved kink rate expression, we have studied the steady state morphology of paracetamol crystals at low supersaturation to understand the morphology transition induced by the solvent effect and compared our predictions with experimental measurements. The model is able to capture the variation in the shape of paracetamol crystals grown from different solvents with reasonable accuracy.