Magnetic dipole systematics in the rare-earth region

In IBA descriptions of the magnetic dipole properties of rare-earth nuclei, the authors consider the effect of the inclusion of the g boson and high-spin intruder shells. Simple microscopic models are presented which ascribe to the g boson some of the effects of the fermion intruder shells the h11/2 and i13/2 orbits, and the consequences of such a model, as an extension of the proton-neutron (sd) IBA-2, are outlined.