Band mixing is used to reproduce the collective bands associated with shape coexistence in even-even osmium, platinum, mercury, and lead nuclei. The properties of the unperturbed bands are examined. The dependence of the unperturbed $2^{+}$→$0^{+}$ energies of the prolate intruder bands on ${\mathit{N}}_{\mathrm{\pi }}$${\mathit{N}}_{\nu }$ is similar to that of the unperturbed normal bands if the intruder configurations are assumed to involve 4-proton, 4-hole excitations. The variation is reproducible using a restricted 2-component model of interacting proton and neutron shells.

• Received 5 October 1993

DOI:https://doi.org/10.1103/PhysRevC.49.3324