NIST Atomic Ionization Energies Output

NIST Physical Measurement Laboratory

NIST Atomic Spectra Database Ionization Energies Data Mt (all spectra) 94 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 ^a (cm^-1)
(403 000)


(758 000)
(879 000)
(1 508 000)
(1 629 000)
(1 903 000)
(2 073 000)
(2 331 000)
(2 565 000)
(2 791 000)
(3 113 000)
(3 275 000)
(3 589 000)

(8 348 000)
(8 646 000)
(8 969 000)
(9 308 000)
(9 638 000)
(9 955 000)
(10 571 000)
(10 905 000)
(11 268 000)
(11 606 000)






















(36 005 000)
(36 706 000)
(37 448 000)
(38 239 000)
(38 981 000)
(39 715 000)
(41 626 000)
(42 384 000)
(43 215 000)
(43 989 000)
(47 127 000)
(47 861 000)
(48 667 000)
(49 410 000)
(56 741 000)
(57 653 000)
(59 967 000)
(60 863 000)
(92 415 000)
(94 044 000)
(95 762 000)
(97 609 000)
(99 359 000)
(101 045 000)
(106 473 000)
(108 288 000)
(110 272 000)
(112 103 000)
(117 225 000)
(118 789 000)
(120 507 000)
(122 080 000)
(144 478 000)
(146 519 000)
(150 535 000)
(152 423 000)
(295 764 000)
(299 950 000)
(304 636 000)
(308 878 000)
(391 534 000)
(398 123 000)
(405 665 000)

(1 584 010 000)
(1 609 920 000)

Notes:
^aIf the listed ionization energy is blank, it is unknown. Only the ground state is known.
^bUncertainty of the listed value is unknown.

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

NIST Physical Measurement Laboratory