A new three-parameter formula is presented and is used to analyze systematically the rotational spectra up to very high spins (below band crossing). An overall and excellent agreement between the calculated and the observed spectra is obtained for all the actinide and the rare-earth deformed nuclei. In the derivation of this formula from the phenomenological Bohr Hamiltonian, a small axial asymmetry and vibrational effects (including anharmonic vibration) have been taken into account.

• Received 24 October 1988

DOI:https://doi.org/10.1103/PhysRevC.39.1617