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

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Despite its terrestrial abundance and astrochemical significance, many aspects of the phase diagram of solid carbon dioxide remain uncertain or unknown. The observed transition pressures from cubic to orthorhombic phase range widely from 2.5 GPa at 80 K to above 18 GPa at room temperature. The vibrational Raman bands that appear at higher pressure and serve as a decisive proof of the existence of the orthorhombic phase have never been assigned. Here we introduce a general ab initio computational method that can predict the Gibbs free energies and thus phase diagrams of molecular crystals. Using this with secondorder Møller-Plesset perturbation theory, we obtain the transition pressure of 13 GPa at 0 K with small temperature dependence, which is in line with many experiments. We also computationally reproduce the vibrational Raman bands and explain the pressure dependence of the structure parameters and Raman band positions of both phases quantitatively.

The central kinetic processes defining layer-bylayer crystal growth or dissolution are the attachment and detachment rates of growth units at kink sites; the net balance of these activated processes leads to either crystal growth or dissolution. Various sets of rate expressions for attachment and detachment processes have been used in the literature, in each case attempting to most appropriately capture the underlying surface chemistry. We examine these proposals with specific attention to thermodynamics and detailed balance criteria and then recommend which expressions to adopt.