The capacity of viscous-plastic flow canals origination in dislocation-free nanocrystals with face-centred and cubic-centred crystal lattices, located in mechanical field, is revealed by analytical calculations computer simulation. As shown, the atoms in chains, located in section of stress concentration, during vibrations may to create the vacancies. It promotes to formation an ordered structure of vacancy defects. Such structure can be considered as nucleus of hydrodynamic flow canals, which leads to localization of plastic deformation in them. Modelling is carried out by the molecular dynamics method using grid-technology.