NIST Atomic Ionization Energies Output

NIST Physical Measurement Laboratory

NIST Atomic Spectra Database Ionization Energies Data W (all spectra) 74 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)
63 427.7
[132 000]
[209 900]
[308 200]
[416 100]
[522 370]
[984 100]
[1 139 000]
[1 292 000]
[1 444 000]
[1 685 000]
[1 868 000]
[2 083 000]
[2 345 000]
[2 624 000]
[2 919 000]
[3 129 000]
[3 393 000]
[3 727 000]
[4 054 000]
[4 383 000]
[4 795 000]
[5 167 000]
[5 530 000]
[5 921 000]
[6 327 000]
[6 722 000]
[7 109 000]
[9 132 000]
[9 517 000]
[9 924 000]
[10 351 000]
[10 768 000]
[11 185 000]
[11 775 000]
[12 198 000]
[12 656 000]
[13 080 000]
[14 758 000]
[15 187 000]
[15 652 000]
[16 089 000]
[17 334 000]
[17 825 000]
[18 990 000]
[19 471 100]
32 720 000
[33 712 000]
[34 757 000]
[35 856 000]
[36 926 000]
[37 983 000]
[39 739 000]
[40 833 000]
[42 017 000]
[43 133 000]
[46 130 000]
[47 104 000]
[48 154 000]
[49 144 000]
[53 200 000]
[54 320 000]
[56 460 000]
[57 510 000]
[125 550 000]
[128 210 000]
[131 080 000]
[133 790 000]
[149 022 000]
[152 213 000]
[156 169 000]
(158 784 300)
(638 645 400)
(651 340 300)

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