Ionic radii of heavy actinide(III) cations

Summary Experimentally determined ionic radii ( r i ) of heavy actinides decrease irregularly with increasing of atomic number. In order to understand sources of this irregularity ionic radii of heavy actinides were compared with the radii of the maximum charge density ( R max ) of the outermost orbital radii of these cations. From the linear dependence of ionic radii on 2 j +1 weighted R max of the 6 p 1/2 and 6 p 3/2 orbitals new values of r i equal to 91.5 pm and 90.3 pm for Fm 3+ and Md 3+ , respectively, were calculated.