  Calculating abundance stratifications in ApBp/HgMn star atmospheres, we are
considering mass-loss in addition to atomic diffusion in our numerical code in
order to achieve more realistic models. These numerical simulations with
mass-loss solve the time dependent continuity equation for plane-parallel
atmospheres; the procedure is iterated until stationary concentrations of the
diffusing elements are obtained throughout a large part of the stellar
atmosphere. We find that Mg stratifications in HgMn star atmospheres are
particularly sensitive to the presence of a mass-loss. For main-sequence stars
with $T_{\rm{eff}}\approx 12000$ K, the observed systematic mild
underabundances of this element can be explained only if a mass-loss rate of
around $4.2\,10^{-14}$ solar mass per year is assumed in our models. Numerical
simulations also reveal that the abundance stratification of P observed in the
HgMn star HD53929 may be understood if a weak horizontal magnetic field of
about 75G is present in this star. However, for a better comparison of our
results with observations, it will be necessary to carry out 3D modelling,
especially when magnetic fields and stellar winds -- which render the
atmosphere anisotropic -- are considered together.
