Abstract

The observed terms of Gd ii can be accounted for by considering the addition of two electrons to just the ⁸S_7/2 ground state of the 4f⁷ core. With the use of matrices containing both electrostatic and spin-orbit interactions we have derived parameters that yield a good least-squares fit to the experimental levels. Our results reveal extensive intermediate coupling within the configurations and strong electrostatic interactions between 4f⁷(⁸S)5d6s, 4f⁷(⁸S)5d², and between 4f⁷(⁸S)6p6s, 4f⁷(⁸S)5d6p. Tables of observed and calculated energy levels, calculated g_J values, and percentage compositions of eigenstates are presented. The significance of the configuration interaction is discussed and attention is drawn to an indeterminacy in the over-all phase of the configuration interaction parameters.

© 1965 Optical Society of America

Energy Levels of the First Spectrum of Europium (Eu i)†

G. Smith and B. G. Wybourne
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Configuration Interaction in the 4f³ Configuration of Pr iii*

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Extension of the Analysis of Singly Ionized Gadolinium (Gd ii)*

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