  We analyze the local level occupation of a spinless, interacting two-level
quantum dot coupled to two leads by means of Wilson's numerical renormalization
group method. A gate voltage sweep, causing a rearrangement of the charge such
that the system's energy is minimized, leads to oscillations, and sometimes
even inversions, in the level occupations. These charge oscillations can be
understood qualitatively by a simple Hartree analysis. By allowing a relative
sign in one tunneling matrix element between dot and leads, we extend our
findings to more generic models.
