Helmholtz free energy functional for generalized lattice model is reduced to Ginzburg- Landau-like form. Connections between interatomic potentials characteristics and parameters of Ginzburg-Landau-like functional are established. Equations for equilibrium distributions of species in multicomponent systems are derived. Equations of rearrangement kinetics of multicomponent systems are obtained. Description of the rearrangement processes via non-classical partial differential equations is proposed.