  We have performed large-scale shell-model calculations of the half-lives and
neutron-branching probabilities of the r-process waiting point nuclei at the
magic neutron numbers N=50, 82, and 126. The calculations include contributions
from allowed Gamow-Teller and first-forbidden transitions. We find good
agreement with the measured half-lives for the N=50 nuclei with charge numbers
Z=28-32 and for the N=82 nuclei 129Ag and 130Cd. The contribution of forbidden
transitions reduce the half-lives of the N=126 waiting point nuclei
significantly, while they have only a small effect on the half-lives of the
N=50 and 82 r-process nuclei.
