  Experimental studies of 152Sm using multiple-step Coulomb excitation and
inelastic neutron scattering provide key data that clarify the low-energy
collective structure of this nucleus. No candidates for two-phonon
beta-vibrational states are found. Experimental level energies of the
ground-state and first excited (0+ state) rotational bands, electric monopole
transition rates, reduced quadrupole transition rates, and the isomer shift of
the first excited 2+ state are all described within ~10% precision using
two-band mixing calculations. The basic collective structure of 152Sm is
described using strong mixing of near-degenerate coexisting quasi-rotational
bands with different deformations.
