  The transition density $n_t$ and pressure $P_t$ at the inner edge between the
liquid core and the solid crust of a neutron star are analyzed using the
thermodynamical method and the framework of relativistic nuclear energy density
functionals. Starting from a functional that has been carefully adjusted to
experimental binding energies of finite nuclei, and varying the density
dependence of the corresponding symmetry energy within the limits determined by
isovector properties of finite nuclei, we estimate the constraints on the
core-crust transition density and pressure of neutron stars: $0.086 \ {\rm
fm}^{-3} \leq n_t < 0.090 \ {\rm fm}^{-3}$ and $0.3\ {\rm MeV \ fm}^{-3} < P_t
\leq 0.76 \ {\rm MeV \ fm}^{-3}$.
