Calculation of the Rydberg Energy Levels for Francium Atom

Based on the weakest bound electron potential model theory, the Rydberg energy levels and quantum defects of nsS21/2(n=8--50), ndD23/2(n=6--50), and ndD25/2(n=6--50) spectrum series for francium atom are calculated. The calculated results are in excellent agreement with the 74 known experimentally measured levels (the absolute difference is less than 0.03 cm-1) and 58 energy levels for highly excited states are predicted