  The key elements of the Unified Model are reviewed and checked against modern
experimental data. For medium-mass or heavy nuclei it is found that separation
between collective and intrinsic degrees freedom becomes invalid for after
exciting five to ten collective quanta along the yrast line and two quanta
above it. The microscopic derivation of the Bohr Hamiltonian by means of
adiabatic time-dependent mean field theory is presented and results compared
with experiment. The description of the strong coupling between the rotational
and intrinsic degrees of freedom in framework of the rotating mean field is
described from a conceptual point of view. The classification of rotational
bands as configurations of rotating quasiparticles is introduced. Using the
concept of spontaneous symmetry breaking the microscopic underpinning of the
rotational degrees is refined. Resulting phenomena, as tilted-axis rotation,
transverse wobbling, chirality, magnetic rotation, and band termination are
discussed.
