  We study one-quasiproton excitations in the rare-earth region in the
framework of the nuclear Density Functional Theory in the
Skyrme-Hartree-Fock-Bogoliubov variant. The blocking prescription is
implemented exactly, with the time-odd mean field fully taken into account. The
equal filling approximation is compared with the exact blocking procedure. We
show that both procedures are strictly equivalent when the time-odd channel is
neglected, and discuss how nuclear alignment properties affect the time-odd
fields. The impact of time-odd fields on calculated one-quasiproton bandhead
energies is found to be rather small, of the order of 100-200 keV; hence, the
equal filling approximation is sufficiently precise for most practical
applications. The triaxial polarization of the core induced by the odd particle
is studied. We also briefly discuss the occurrence of finite-size spin
instabilities that are present in calculations for odd-mass nuclei when certain
Skyrme functionals are employed.
