  The quantum dynamics of coupled subsystems connected to a thermal bath is
studied. In some of the earlier work the effect of intercenter coupling on the
dissipative part was neglected. This is equivalent to a zeroth-order
perturbative expansion of the damping term with respect to the intercenter
coupling. It is shown numerically for two coupled harmonic oscillators that
this treatment can lead to artifacts and a completely wrong description, for
example, of a charge transfer processes even for very weak intercenter
coupling. Here we perform a first-order treatment and show that these artifacts
disappear. In addition, we demonstrate that the thermodynamic equilibrium
population is almost reached even for strong intercenter coupling strength.
