  Behavior of the mixture of particles and dimers moving with different jump
rates at reconstructed surfaces is described. Collective diffusion coefficient
is calculated by the variational approach. Anisotropy of the collective
particle motion is analyzed as a function of jump rates and local particle
density. Analytic expressions are compared with the results of Monte Carlo
simulations of diffusing particle and dimer mixture. Direction of driven
diffusive motion of the same system depends on the jump anisotropy and on the
value of driving force. Driven motion results in the particle and dimer
separation when the directions of their easy diffusion axes differ. It is shown
that in such case trapping sites concentrated at some surface areas act as
filters or barriers for particle and dimer mixtures.
