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and the electron configuration of the particular uranium atom or ion. The electronic partition function of i-times ionized uranium is given by (39)


          u   =    giCe-Xij/kT



   -=   , + 1   -X/kT +       e-X2/kT +            (4.35)


where

        gi   = statistical weight of the j-th term of
          '~J  i-times ionized uranium

        X    = exitation energy level of the j-th term
               of i-times ionized uranium


The j-th statistical weight for the i-times ionized uranium is (40)


          9i'j = (2Lij       2S    + 1)            (4.36)

where

        L.   = orbital angular momentum

        S.   = spin angular momentum


        The statistical weights of the uranium atom are

calculated from the spectroscopic data of Steinhaus, Blaise, and Diringer (41). Since experimental uranium ion data from which the necessary Li'j and Si,j values can be determined are not presently available, the iso-electronic