Octupole correlation in near-proton-drip-line nuclei 106,108Te has been investigated using improved total Routhian surface calculations with the inclusion of reflection-asymmetric deformations. It is found that 106,108Te have reflection-symmetric shapes at low spins, then become octupole deformed at rotational frequencies ¶ÿ°÷0.50 - 0.60 MeV/\hbar. The onset of strong octupole correlation is consistent with the observation of octupole bands in 108Te. The octupole structure predicted for 106Te would be accessible in experiments.

Octupole properties in even®Ceven 220®C230 U isotopes have been investigated using improved total Routhian surface calculations with the inclusion of reflection-asymmetric deformations. We pay attention to the evolution of octupole properties with increasing nucleon and rotational frequency. 222 U is predicted to have static octupole deformation up to high spins. A shape transition from reflection-symmetry to reflection-asymmetry happens across 228 92 U 136 with decreasing neutron number in uranium isotopes or decreasing proton number in N = 136 isotones. Our calculations were compared with previous calculations and available experiments.

An angular momentum projected potential-energy-surface (PES) calculation, which takes both rotational symmetry restoration and multi-quasiparticle excitation into account, is developed by using the macroscopic-microscopic model and the projected shell model (PSM). Within this method, it may become possible to modify the excitation spectra which are influenced by shape-softness of nuclei, including high- K states. As our first example, this method is adopted to study the collective and multi-quasiparticle excitations of 178 Hf, and the results are in good agreement with the existing experimental data. In addition, as for the dominant structure of non-collective 6 + bands, the conflict between experimental result and the previous PSM calculation is clarified.

High-spin states in 157 Yb have been populated in the 144 Sm( 16 O, 3n) 157 Yb fusion-evaporation reaction at a beam energy of 85 MeV, and two rotational bands have been established for the first time. Within the framework of the triaxial particle-rotor model, the energy spectra and single-particle configurations of 157 Yb are investigated. The calculated energy spectra agree well with the experimental data. The newly observed ν f 7/2 band, and the previously known ν i 13/2 band in 157 Yb, are also discussed by means of Total-Routhian-Surface methods. The structural characters observed in 157 Yb provide evidence for the shape coexistence of three distinct shapes: prolate, triaxial and oblate. At higher spins, both the ν f 7/2 band and the ν i 13/2 band in 157 Yb undergo a shape evolution with sizable alignments occurring.