  High precision atomic data is indispensable for experiments involving studies
of fundamental interactions, astrophysics, atomic clocks, plasma science, and
others. We develop new parallel atomic structure codes and explore the
difficulties of load-balancing in these codes. Efficient load-balancing of
matrix elements for many-electron systems is very difficult due to the
intrinsic nature of the computational methods used to compute them. By
arithmetically selecting determinants for each core, we achieve very even
workload distribution, and attain near-perfect linear scalability and
efficiency with the number of cores. We also implement dynamic memory
allocation to minimize memory usage and remove the need for users to set
certain array parameters. Our newly developed codes enable computations that
were not possible before due to lack of memory or prohibitive computation
times, and allow a broader range of correlations to be investigated in a
shorter period of time. This includes calculations correlating all 60 electrons
in the highly charged Ir$^{17+}$ ion and calculations predicting the $3C/3D$
line intensity ratio in Fe$^{16+}$. Our new code package will also be used to
produce large volumes of high precision atomic data for a new online portal
being developed at the University of Delaware.
