  The electronic and magnetic properties of ferromagnetic doped manganites are
investigated by means of model tight-binding and \textit{ab initio}
self-interaction corrected local spin density approximation calculations. It is
found that the surface alone by breaking the cubic symmetry induces a
difference in the occupation of the two $e_{g}$ orbitals at the surface. With
\textit{ab initio} calculations we found surface localisation of one orbital
and hence a change in the Mn valency from four in the bulk to three at the
sub-surface. Different surface or disordered interface induced localisation of
the orbitals are considered too with respect to the nature and the strength of
the magnetic exchange coupling between the surface/interface and the bulk-like
region.
