Multiplet Strengths for Transitions Involving Equivalent Electrons

Bacher and Goudsmit have shown that the parentage of a term arising from a shell of equivalent electrons is expressible as a linear combination of all the terms of the ion. When two or more terms of a kind occur in the same configuration, however, the method gives only the sum of the parentages of the terms involved. The resulting parentages may be used with the well-known Kronig formulae to calculate multiplet strengths in transition arrays where the jumping electron is equivalent to others in oniy one of the two configurations. At the present time, the method is applicable to all arrays involving equivalent s- and p-electrons, and to arrays involving not more than three equivalent d-electrons. For convenience of calculation a table containing the parentages of terms arising from equivalent electron shells is given. The table also lists the configurations of astro- physical interest to which these parentages may be applied in the calculation of multi- plet strengths