NIST Atomic Ionization Energies Output

NIST Physical Measurement Laboratory

NIST Atomic Spectra Database Ionization Energies Data Eu (all spectra) 63 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)
45 734.74
[90 660]
[200 350]
[346 300]
[510 000]
(714 000)
(844 000)
(970 000)
(1 162 000)
(1 302 000)
(1 474 000)
(1 716 000)
(1 960 000)
(2 120 000)
(2 270 000)
(2 510 000)
[2 778 000]
(4 178 000)
(4 460 000)
(4 759 000)
(5 081 000)
(5 380 000)
(5 718 000)
(6 089 000)
(6 412 000)
(6 759 000)
(7 090 000)
(8 364 000)
(8 695 000)
(9 066 000)
(9 412 000)
(10 074 000)
(10 453 000)
(11 340 000)
[11 743 900]
(20 124 000)
(20 898 000)
(21 753 000)
(22 640 000)
(23 503 000)
(24 374 000)
(25 552 000)
(26 447 000)
(27 407 000)
(28 310 000)
(30 835 000)
(31 625 000)
(32 512 000)
(33 319 000)
(35 488 000)
(36 400 000)
(38 142 000)
(39 021 000)
(87 753 000)
(89 955 000)
(92 407 000)
(94 681 000)
(102 578 000)
(105 255 000)
(108 578 000)
(110 809 100)
(450 589 090)
(460 709 000)

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