Theg R -factor of rare-earth nuclei in the Geometric Collective Model

A parameter-free expression for the collective magnetic dipole operator ofee-nuclei is derived within the Geometric Collective Model. Using this result we give an analytical formula for the (g _R ?Z/A)-value of the lower spin groundstate band members foree-nuclei. The general procedure is explained discussing the results (energies, B(E2)-values and quadrupole moments) for^166–170Er-isotopes extensively. The groundstate bandg _R -factors of the isotopes^166–170Er,^153–160Gd,^160–164Dy,^170–174Yb are calculated and compared with experimental data and results of other models.