  We investigate the inner crust structure of neutron stars using the
Skyrme-Hartree-Fock approach with the Coulomb interaction treated beyond the
Wigner-Seitz approximation. Our results suggest that the shell effects
associated with unbound neutrons play an important role and, in particular,
lead to complicated phase transition pattern between various nuclear phases (as
a function of the density). Namely, we show that the relative energies of
different phases are rapidly oscillating functions of the neutron density. In
the semiclassical approach this behavior is explained as an interference effect
due to periodic orbits of similar lengths. We discuss also the dependence of
the shell effects on pairing correlations.
