  Calculation of energy of migration for number of molecular crystals consisting of centrosymmetrical and non-centrosymmetrical molecules was carried out by using a method of atom-atom potentials. It is shown, that the potential barrier is symmetrical for crystals consisting of centrosymmetrical molecules, but not symmetrical for the mixed crystals and crystals consisting of non-centrosymmetrical molecules. Thus it is possible to influence quantity of migration energy, growing the mixed crystals with a particular arrangement of components. 
Influence of the Random Arrangement of Molecules on Energy of Vacancies   Migration