Abstract
<jats:p>Bands structure and nuclear shape in the N ≈ 90 region are investigated using the interacting boson model. The energy levels and the energy ratios are investigated. We have studied the ratio δE(J−)/E(2+1) versus the mass number for the J− = 1− to 11− states. The ratio E(J+i)/E(2+1) of the yrast bands versus angular momentum (J+i) has been calculated. The 152Sm, 154Gd and 160Er nuclei have a rotational SU(3) character, while the 156Dy, 170W, and 176Os nuclei reflect the X(5) character. To investigate the shape evolution, the potential energy surface as a function of β2 and β3 are plotted. The obtained results are compared with available empirical data. The results are in general good agreement for energy spectra, while they show reasonable agreement for other calculations or at least their overall trend.</jats:p>