Fully self-consistent band calculation has been performed for slab phase in neutron-star inner crust , using the BCPM energy density functional .
Optimized slab structure is calculated at given baryon density either with the fixed proton ratio or with the beta-equilibrium condition .
Numerical results indicate the band gap of in order of keV to tens of keV , and the mobility of dripped neutrons are enhanced by the Bragg scattering , which leads to the macroscopic effective mass , \bar { m } ^ { * } _ { z } / m _ { n } = 0.65 \sim 0.75 near the bottom of the inner crust in neutron stars .
We also compare the results of the band calculation with those of the Thomas-Fermi approximation .
The Thomas-Fermi approximation becomes invalid at low density with high proton ratio .