COLLECTIVE EXCITED STATES IN EVEN–EVEN NUCLEI WITH QUADRUPOLE AND OCTUPOLE DEFORMATIONS

Deformed even–even nuclei with quadrupole and octupole deformations are investigated on the basis of a nonadiabatical collective model. It is shown that the model satisfactorily describes energy levels of the yrast and first nonyrast bands with alternating parity in the rare-earth nuclei 150Nd, 152, 154Sm, 154Gd, 156Dy, 162, 164Er and the actinides 232, 234, 236, 238U. In the nuclei 156, 158Gd, 224Ra, 228Th and 240Pu the energy levels of second nonyrast bands are also described. The structure of the considered alternating-parity bands is examined in terms of odd–even staggering diagrams.