Improved i 4 1snl ionization energy, energy levels, and Lamb shifts for 1sns and 1snp terms

The consistencies of calculated term values (ionization energies) for various 1snl terms having n=5–8, l=1–5 are tested by microwave-spectroscopic and other available data. The most accurate n P, n D, and n F term values obtained from published variational calculations are generally found to be consistent, within the estimated uncertainties, with more accurate n G and n H energies from core-polarization theory [R. J. Drachman, Phys. Rev. A 26, 1228 (1982)]. The n 3D and n 1D term values from variational calculations [A. Kono and S. Hattori, Phys. Rev. A 34, 1727 (1986)] are confirmed within uncertainties as small as 10−4 cm−1 (n=8), although the D1 values are systematically too large by amounts within the uncertainties. The ionization energy EI has accordingly been reevaluated by using only the calculated n 3D term values (n=4,5) and available experimental measurements: The resulting EI value is 198 310.772 27(40) cm−1 with respect to the 2 S3 level at 159 856.077 60 cm−1.