“…One-quadrupole-phonon MSSs were identified all across the nuclear chart; in the mass A ≈ 90 region [6,12,13], as well in the mass A ≈ 130 region [14][15][16][17][18][19] and, most recently, in the mass A ≈ 200 region [20,21]. The experimental information accumulated up to now suggests that pronounced one-phonon MSSs can be expected when both protons and neutrons occupy orbitals with high angular momenta as in the case of 212 Po [20].…”