The Lanthanide Elements in Stellar and Laboratory Spectra
The lanthanide elements (Z=57?71) are characterized by the filling of the 4f electronic subshell, which lies close in energy to the 5d and 6s subshells. As a result, the lanthanide spectra can be quite complicated in terms of the number of optical spectral lines, and in some cases their hyperfine structure and isotopic shifts are extremely large. These characteristics have great implications for a