Coexisting single-particle excitations and octupole correlations in the transitional nucleus Ra217

The level structure of the transitional nucleus $^{217}\mathrm{Ra}$ has been extended with the addition of around 20 new transitions. The discrepancies between the placements of several transitions reported in the earlier studies are resolved. The newly established negative-parity sequence at low excitation energies hints at the expected parity-doublet structures in this nucleus. The properties of the observed simplex bands are compared with that of similar bands in neighboring nuclei. Since the presence of parity-doublet structures reflects octupole correlations, theoretical calculations using reflection-asymmetric triaxial particle rotor model (RAT-PRM) have been performed. A comparison of the observed features of the simplex bands with the predictions of the RAT-PRM calculations suggests that $^{217}\mathrm{Ra}$ exhibits an intermediate behavior between the extremes of spherical and octupole-deformed nuclei. The termination of the simplex bands at intermediate energies and the structures lying above reflect the dominance of the single-particle excitations at higher excitation energies.