The paper presents a comprehensive study of the multiscale physics of atomic nuclei, focusing on the transition from traditional shell structure to deformation and coexisting shapes as nuclear binding approaches the neutron and proton driplines. The authors develop a unified, non-perturbative quantum many-body framework that captures both short- and long-range correlations, using modern nucleon-nucleon and three-nucleon forces from chiral effective field theory. Short-range correlations, which dominate the binding energy, are included within a symmetry-breaking framework, while long-range correlations are incorporated through symmetry projection techniques. The method accurately reproduces experimental data for low-lying collective states and electromagnetic quadrupole transitions in 20-30Ne. The study reveals coexisting spherical and deformed shapes in 30Ne, indicating the breakdown of the magic neutron number N = 20 as the key nucleus 28O is approached. The authors also predict that the dripline nuclei 32,34Ne are strongly deformed and collective. By developing reduced-order models for symmetry-projected states, they perform a global sensitivity analysis, finding that subleading singlet S-wave contact and pion-nucleon coupling strongly impact nuclear deformation in chiral effective field theory. The techniques developed in this work clarify how microscopic nuclear forces generate the multiscale physics of nuclei, spanning collective phenomena and short-range correlations.The paper presents a comprehensive study of the multiscale physics of atomic nuclei, focusing on the transition from traditional shell structure to deformation and coexisting shapes as nuclear binding approaches the neutron and proton driplines. The authors develop a unified, non-perturbative quantum many-body framework that captures both short- and long-range correlations, using modern nucleon-nucleon and three-nucleon forces from chiral effective field theory. Short-range correlations, which dominate the binding energy, are included within a symmetry-breaking framework, while long-range correlations are incorporated through symmetry projection techniques. The method accurately reproduces experimental data for low-lying collective states and electromagnetic quadrupole transitions in 20-30Ne. The study reveals coexisting spherical and deformed shapes in 30Ne, indicating the breakdown of the magic neutron number N = 20 as the key nucleus 28O is approached. The authors also predict that the dripline nuclei 32,34Ne are strongly deformed and collective. By developing reduced-order models for symmetry-projected states, they perform a global sensitivity analysis, finding that subleading singlet S-wave contact and pion-nucleon coupling strongly impact nuclear deformation in chiral effective field theory. The techniques developed in this work clarify how microscopic nuclear forces generate the multiscale physics of nuclei, spanning collective phenomena and short-range correlations.