After arriving at a Hamiltonian H (based on chiral EFT or other models) one must solve the Schrödinger equation H | Ψ Ψ ⟩ ⟩ = E | Ψ Ψ ⟩ ⟩ , where | Ψ Ψ ⟩ ⟩ is the many-body wavefunction of the A nucleons in the nucleus. Various ab initio methods have been devised to numerically find solutions to this equation: