Anomaly in the Charge Radii and Nuclear Structure

The axially deformed relativistic mean field theory is applied to study the isotope shift of charge distributions of odd-Z Pr isotope chain. The nuclear structure associated with the shell and the isotope effect is investigated. The mechanism of the kink in the isotope shift at the neutron magic number N=82 is revealed to be dependent on the neutron energy level structure at the Fermi energy, demonstrating that the spin--orbit coupling interaction and p--n attraction are well described by the relativistic mean field theory.