  It is well known that within self-consistent Random Phase Approximation (RPA)
on top of Hartree-Fock (HF), the translational symmetry should be restored. Due
to approximations at the level of the practical implementation, this
restoration may be only partial. As a result, one has spurious contributions in
the physical quantities that are extracted from RPA. While there are several
recipes in the literature to overcome this drawback in order to produce
transition densites or strength functions that are free from spurious
contamination, there is no formalism associated with the full RPA response
function. We present such formalism in this paper. Our goal is to avoid
spurious contamination when the response function is used in many-body
frameworks like the particle-vibration coupling theory.
