  Phenomenological approach to inhomogeneous nuclear matter is useful to
describe fundamental properties of atomic nuclei and neutron star crusts in
terms of the equation of state of uniform nuclear matter. We review a series of
researches that we have developed by following this approach. We start with
more than 200 equations of state that are consistent with empirical masses and
charge radii of stable nuclei and then apply them to describe matter radii and
masses of unstable nuclei, proton elastic scattering and total reaction cross
sections off unstable nuclei, and nuclei in neutron star crusts including
nuclear pasta. We finally discuss the possibility of constraining the density
dependence of the symmetry energy from experiments on unstable nuclei and even
observations of quasi-periodic oscillations in giant flares of soft gamma-ray
repeaters.
