  We propose a two-point flux approximation finite-volume scheme for the
approximation of two cross-diffusion systems coupled by a free interface to
account for vapor deposition. The moving interface is addressed with a cut-cell
approach, where the mesh is locally deformed around the interface. The scheme
preserves the structure of the continuous system, namely: mass conservation,
nonnegativity, volume-filling constraints and decay of the free energy.
Numerical results illustrate the properties of the scheme.
