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The zinc-based compound crystals, which are composed of zinc-anion coordinate tetrahedrons have two kinds of structure:one is wurtzite and the other is sphalerite.In this article the formation process and the ideal morphology of the sphalerite crystals are studied by calculating the stability energy of the crystal growth unit on the basis of the model of anion coordination polyhedron.The favorable growth unit for the growth of the sphalerite crystal is the tetrahedron.Thus the ideal morphology of sphalerite crystals is tetrahedron.The growth rate of the positive polar plane is different from that of the negative polar plane.It is proved by the calculation that zincoxide crystals are impossible to exist in sphalerite,so are zincsulphide crystals in wurtzite.

The calculation results of the stability energy of the growth unit for hydrothermal barium titanate crystallites are reported and the nucleation as well as the growth of the crystallites under hydrothermal conditions are discussed.

Nucleation and formation of barium titanate crystallites under hydrothermal conditions was studied using a mathematical model and calculation of the stabilization energy of the growth unit on the basis of synthesis experiments.