  We present an overview of the coupled-channels optical model and the
Hauser-Feshbach theory code CoH$_3$, which focuses on the nuclear reaction
calculations in the keV to tens of MeV region with special attention to the
nuclear deformation. The code consists of three major sections that undertake
the one-body potential mean-field theory, the coupled-channels optical model,
and the Hauser-Feshbach statistical decay. There are other complementary
segments to perform the whole nuclear reaction calculations, such as the
direct/semidirect radiative capture process, pre-equilibrium process, and
prompt fission neutron emission.
