We report on the computational characteristics of ab initio nuclear structure calculations in a symmetry-adapted no-core shell model (SA-NCSM) framework. We examine the computational complexity of the current implementation of the SA-NCSM approach, dubbed LSU3shell, by analyzing ab initio results for 6Li and 12C in large harmonic oscillator model spaces and SU3-selected subspaces. We demonstrate LSU3shell's strong-scaling properties achieved with highly-parallel methods for computing the many-body matrix elements. Results compare favorably with complete model space calculations and significant memory savings are achieved in physically important applications. In particular, a well-chosen symmetry-adapted basis affords memory savings in calculations of states with a fixed total angular momentum in large model spaces while exactly preserving translational invariance.
Publication Source (Journal or Book title)
Computer Physics Communications
Dytrych, T., Maris, P., Launey, K., Draayer, J., Vary, J., Langr, D., Saule, E., Caprio, M., Catalyurek, U., & Sosonkina, M. (2016). Efficacy of the SU(3) scheme for ab initio large-scale calculations beyond the lightest nuclei. Computer Physics Communications, 207, 202-210. https://doi.org/10.1016/j.cpc.2016.06.006