Nuclear surface and curvature properties for SLy Skyrme forces and nuclei in the inner neutron-star crust

The properties of nuclear surface, including lowest order curvature terms, below and above the neutron drip point, are studied using recent SLy Skyrme models of the effective nucleon-nucleon interaction. Calculations are performed using the Extended Thomas-Fermi description of the energy functional, with variational determination of the surface density profiles. Numerical results are compared with those obtained for older Skyrme forces, and applied in the Compressible Liquid Drop Model calculations of neutron rich nuclei in ground state of neutron-star crust. Five possible types of nuclear structures are considered, characterized by spherical, cylindrical, and plane nuclear matter-neutron gas interface. Spherical nuclei are energetically preferred, down to the limiting density marking the transition into a homogeneous nucleon-electron liquid.