  Based on perturbation theory, we study the dynamics of how dark matter and
dark energy in the collapsing system approach dynamical equilibrium while
interacting. We find that the interaction between dark sectors cannot ensure
the dark energy to fully cluster along with dark, leading to the energy
non-conservation problem in the collapsing system We examine the cluster number
counts dependence on the interaction between dark sectors. Furthermore, we
analyze how dark energy inhomogeneities affect cluster abundances. It is shown
that cluster number counts can provide specific signature of dark sectors
interaction and dark energy inhomogeneities.
