Parametric study of the 5d2, 5d6s, and 5d6p configurations in the YbI isoelectronic sequence

Data available on the 5d(2), 5d6s, and 5d6p configurations in the Yb I isoelectronic sequence have been critically reviewed by means of calculations with the orthogonal operators. The study included ions from Ta rv through Hg XI. Quite good agreement of the calculations with the experimental data for the ions from Ta Iv through Au X has been achieved. A temporarily assigned value for the 5d(2) S-1(0) level in the analysis of Re VI has been confirmed, and a previously unknown 5d6p P-3(0) level in Au X has been established. For Hg XL, at least three of nine published levels in the 5d2 configuration and four of eleven levels in the 5d6p configuration are suspect because of their abnormal deviations from the calculated positions. The isoelectronic evolution of the parameter A,,. that describes the two-particle magnetic cls interaction in the 5d6s configuration as well as of the two effective parameters S-1 and S-2 that describe higher-order effects in the 5d6p configuration was studied for the first time to the author's knowledge in the Yb I sequence. The present calculations based on the orthogonal operators resulted in 5-10 times better agreement with the experimental data than did the conventional calculations. (C) 2001 Optical Society of America.