We address the problem of generating a many-nucleon basis for ab initio nuclear structure modeling, which quickly becomes a significant runtime bottleneck for large model spaces. We first analyze the original basis generation algorithm, which does not employ multi-threading parallel paradigm.
Based on the analysis, we propose and empirically evaluate a new efficient scalable basis generation algorithm. We report a reduction of basis generation runtime by a factor of 42 on the Blue Waters supercomputer and by two orders of magnitude on our test-bed computer system with Broadwell CPUs.