An approach combining atomistic molecular dynamics (MD) and thermodynamic simulations has been applied to predict the distribution of components in binary Ni-Cu and Au-Ag nanoparticles consisting of 2000 atoms (of about 4 nm in size). The term ‘thermodynamic simulation’ has referred to solving, in some approximations, the Butler equation for a core-shell particle model. Both atomistic and thermodynamic approaches predict the surface segregation of Cu atoms in Ni-Cu nanoparticles and segregation of Ag to the surface of Au-Ag nanoalloys. Then, contrary to the Ni-Cu systems, some Au-Ag nanoparticles demonstrated an onion-like structure with the outer Ag monolayer. The results of MD and thermodynamic simulations agree with each other and with some available direct and indirect experimental data. [ABSTRACT FROM AUTHOR]