Low Even Configurations in the First Spectrum of Ruthenium (Ru i)

The theory of intermediate coupling with configuration interaction is used to calculate energy levels and g values in the 4d65s2, 4d75s, and 4d8 configurations of Ru i. By using fifteen parameters, the positions of fifty-seven observed levels are calculated with a mean deviation of ±54 cm−1 between theory and experiment. There are unexplained differences greater than 500 cm−1 for two other levels, one of which is well confirmed by experiment. Over-all agreement between observed and calculated g values is within ±0.006. Linear relations are obtained between similarly defined electrostatic parameters in the three configurations.