Converged <i>ab initio</i> calculations of heavy nuclei

We propose a novel storage scheme for three-nucleon (3N) interaction matrix elements relevant the normal-ordered two-body approximation used extensively in ab initio calculations of atomic nuclei. This reduces required memory by approximately two orders magnitude, which allows generation 3N with standard truncation ${E}_{3\mathrm{max}}=28$, well beyond previous limit 18. demonstrate that this is sufficient to obtain ground-state energy $^{132}\mathrm{Sn}$ converged within few MeV respect ${E}_{3\mathrm{max}}$ truncation. In addition, we study asymptotic convergence behavior and perform extrapolations un-truncated limit. Finally, investigate impact truncations made when evolving free-space interactions similarity renormalization group. find contribution blocks angular momentum ${J}_{\mathrm{rel}}&gt;9/2$ dominated basis-truncation artifact, vanishes large-space limit, so these computationally expensive components can be neglected. For sets nuclear employed work, resulting binding agrees experimental value theoretical uncertainties. work enables heavy