M. : Science, Main edition of physico-mathematical, literature, 1983. -280s. The book is devoted to the atomic, molecular, as well as microcrystalline structures of mixed crystals. All classes of substances are considered - organic, inorganic, metallic and polymeric. In some cases, the author analyzes a fairly strict expression of the free energy of these systems. However, the construction of such a theory faces great difficulties .. That is why the author dwells in detail on the interpretation of the structures of all these systems from the point of view of the principle of dense packing of particles. It is also shown that this simple geometric principle allows in many cases to predict the structure of various mixed. Crystals.