Quadrupole collective states within the Bohr collective Hamiltonian

The article reviews the general version of the Bohr collective model for the description of quadrupole collective states, including a detailed study the model's kinematics. The general form of the classical and quantum Bohr Hamiltonian is presented together with a discussion of the tensor structure of the collective wave functions and with a short review of various methods of solving the Bohr Hamiltonian eigenvalue equation.The methods of derivation of the classical and quantum Bohr Hamiltonian from the microscopic many-body theory are recalled and the microscopic approach to the Bohr Hamiltonian is applied to interpret collective properties of 12 heavy even-even nuclei in the Hf-Hg region.