NIST Atomic Ionization Energies Output

NIST Physical Measurement Laboratory

NIST Atomic Spectra Database Ionization Energies Data Ta (all spectra) 73 Data Rows Found	Example of how to reference these results: Kramida, A., Ralchenko, Yu., Reader, J., and NIST ASD Team (2024). NIST Atomic Spectra Database (ver. 5.12), [Online]. Available: https://physics.nist.gov/asd [2026, October 26]. National Institute of Standards and Technology, Gaithersburg, MD. DOI: https://doi.org/10.18434/T4W30F BibTex Citation (new window)

Ionization Energy (cm^-1)
60 891.4
[131 000]
(186 000)
(282 000)
[389 340]
[758 250]
(957 000)
(1 122 000)
(1 286 000)
(1 451 000)
(1 720 000)
(1 896 000)
(2 110 000)
(2 450 000)
(2 730 000)
(2 930 000)
(3 195 000)
(3 540 000)
(3 890 000)
(4 240 000)
(4 590 000)
(4 960 000)
(5 310 000)
(5 660 000)
(6 010 000)
(6 360 000)
(6 710 000)
(8 582 000)
(8 953 000)
(9 356 000)
(9 767 000)
(10 179 000)
(10 590 000)
(11 147 000)
(11 566 000)
(12 018 000)
(12 437 000)
(14 099 000)
(14 510 000)
(14 978 000)
(15 405 000)
(16 559 000)
(17 042 000)
(18 180 000)
[18 669 000]
31 445 000
(32 375 000)
(33 416 000)
(34 504 000)
(35 569 000)
(36 593 000)
(38 271 000)
(39 336 000)
(40 521 000)
(41 610 000)
(44 659 000)
(45 611 000)
(46 659 000)
(47 643 000)
(51 329 000)
(52 442 000)
(54 596 000)
(55 652 000)
(122 088 000)
(124 701 000)
(127 605 000)
(130 283 000)
(143 922 000)
(147 172 000)
(151 277 000)
(153 959 200)
(619 853 200)
(632 295 300)

Notes:
^aUncertainty of the listed value is unknown.

If you did not find the data you need, please inform the ASD Team.

NIST Physical Measurement Laboratory