Phase Selection of Calcium Carbonate through the Chirality of Adsorbed Amino Acids

On the phase of it: The phase selection of calcium carbonate (spheres: C gray, Ca green, O red) is determined by chiral amino acids (stick models) present during the crystallization. The interplay of composition and chirality of the crystal surfaces and additives leads to enantiospecific adsorption of the D and L amino acids on chiral surface steps. The resulting surface passivation creates a kinetic barrier, which controls the phase selection.