  The spin and parity dependent nuclear level densities (NLD) are calculated
for medium-heavy nuclei using shell model techniques. The NLD are used to
calculate cross sections and reaction rates of interest for nuclear
astrophysics and nuclear energy applications. We investigate a new approach of
describing the shell model NLD via a constant temperature parametrization. This
approach provides new information about the effects of symmetries on the
temperature of the low-lying nuclear states, and it is shown to be more
versatile for applications.
