Ab initio calculations of nuclei treat a nucleus as a system of A nucleons interacting by realistic two- (NN) and three-nucleon (NNN) forces. Variational Monte Carlo (VMC) followed by Green's function Monte Carlo (GFMC) is a very successful combination for light nuclei. Both increasing computer power and new or improved algorithms have resulted in steady progress in applying this approach to larger nuclei and we now get excellent scalability up to 131,000 cores on Argonne's IBM Blue Gene/P. With the Argonne v₁₈ NN and Illinois NNN potentials, we obtain an excellent description of the properties of nuclei up to A = 12. I will describe these methods, and present recent advances in using the largest computers and some recent results.

Argonne Physics Division Colloquium Schedule