MD simulations have been performed to investigate the interface mixing in the low energy (5-10 eV) deposition of Ag on Cu(001). The statistics of single Ag atom impacts on the Cu(001) surface was studied. Interface mixing initiated by atom impacts on the substrate was found to increase with growth of atom arrival energy and temperature of substrate. It has been shown that the probability of exchange is increased in the vicinity of bridge position between two binding sites. Normal incidence was shown to yield maximum of intermixing. Finally the formulae for concentration profile of impurity atoms in the film has been derived.