Simulations of crystal aggregation and growth: Towards correct crystal area

Simulating crystal growth and aggregation can provide insight into factors that control the final product properties. Classical models involve formation of a volume-equivalent single crystal upon aggregation. This approach does not preserve particle area, resulting in an inadequate model of supersaturation depletion. Alternatively, crystal area can be computed accurately by a Monte Carlo method where each primary particle of an aggregate is described in its full geometric complexity. However, the drawback of this method is its computational cost. Thus, a third method is introduced as a compromise, describing particles by their volume and area and preserving both upon aggregation. The so-obtained two-dimensional model requires growth rate expressions in volume and area. We provide a method for parametrizing these expressions so that total volume and area closely match the values obtained with the method based on full geometric information. The parameters depend on primary particle geometry and the amount of growth.