Structure of Even Erbium Isotopes

All available data on the rotational hands built on collective and two-qnasiparticle levels in eveneven isotopes with N from 88 to 104 are considered. Studies of nuclear spin dependence of inertial parameters, which arc inverse to nuclear moments of inertia, show regularities common to bands in nuclei with the same Z or N and with the same quantum number K, as well as some peculiarities in nuclei with an abnormal energy level structure. Our results confirm the validity of the quasiparticic vibrational model and make it possible to identify a large number of long rotational bands.