| Reference Label | Details |
|---|---|
| NIST Atomic Web | A. Kramida, Yu. Ralchenko, J. Reader, and NIST ASD Team, NIST Atomic Spectra Database (ver. 5.6.1), NIST Standard Reference Database #78, National Institute of Standards and Technology, Gaithersburg, MD 2018 Web: https://physics.nist.gov/asd (ex: http://physics.nist.gov/cgi-bin/AtData/main_asd) Note: latest version (as of Mar 2020) is ver. 5.7 |
| Erickson 1977 | G. W. Erickson, J. Phys. Chem. Ref. Data 6, 831-869 (1977) Energy Levels of One-Electron Atoms |
| note std dev | Originally one std. dev. was given and was multiplied by 2 (for large or unknown number of measurements) or the appropriate Student-t factor (for a smaller number of determinations) to come closer to the desired 95% confidence limit. |