  Based on a microscopic density functional theory we calculate the internal
structure of the three-phase contact line between liquid, vapor, and a
confining wall as well as the morphology of liquid wetting films on a substrate
exhibiting a chemical step. We present a refined numerical analysis of the
nonlocal density functional which describes the interface morphologies and the
corresponding line tensions. These results are compared with those predicted by
a more simple phenomenological interface displacement model. Except for the
case that the interface exhibits large curvatures, we find that the interface
displacement model provides a quantitatively reliable description of the
interfacial structures.
