  We use the finite amplitude method for computing charge-changing Skyrme-QRPA
transition strengths in axially-deformed nuclei together with a modern Skyrme
energy-density functional to fit several previously unconstrained parameters in
the charge-changing time-odd part of the functional. With the modified
functional we then calculate rates of beta-minus decay for all medium-mass and
heavy even-even nuclei between the valley of stability and the neutron drip
line. We fit the Skyrme parameters to a limited set of beta-decay rates, a set
of Gamow-Teller resonance energies, and a set of spin-dipole resonance
energies, in both spherical and deformed nuclei. Comparison to available
experimental beta-decay rates shows agreement at roughly the same level as in
other global QRPA calculations. We estimate the uncertainty in our rates all
the way to the neutron drip line through a construction that extrapolates the
errors of known beta-decay rates in nuclei with intermediate Q values to less
stable isotopes with higher Q values.
