  We compare two approaches to describe the inner crust of neutron stars: on
the one hand, the simple coexistence of a liquid (clusters) and a gas phase,
and on the other hand, the energy minimization with respect to the density
profile, including Coulomb and surface effects. We find that the
phase-coexistence model gives a reasonable description of the densities in the
clusters and in the gas, but the precision is not high enough to obtain the
correct proton fraction at low baryon densities. We also discuss the surface
tension and neutron skin obtained within the energy minimization.
