A physically motivated extension of the ${\mathrm{SU}}_{\mathit{q}}$(2) model of rotational nuclear spectra is introduced, which is applicable in the vibrational and transitional regions as well. The deformation parameter is related to the centrifugal stretching effect, while the new parameter c allows the spectrum to be an expansion in terms of J(J+c) instead of J(J+1), thus describing nuclear anharmonicities in a way similar to the interacting boson model and the generalized variable moment of inertia model.

• Received 25 January 1994

DOI:https://doi.org/10.1103/PhysRevC.50.497