NIST Atomic Ionization Energies Output

NIST Physical Measurement Laboratory

NIST Atomic Spectra Database Ionization Energies Data Sg (all spectra) 95 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)
[63 000]
[138 000]
[208 000]
[286 000]
[381 000]
[478 000]
(879 000)
(984 000)
(1 226 000)
(1 371 000)
(1 613 000)
(1 807 000)
(2 024 000)
(2 299 000)
(2 468 000)
(2 734 000)

(7 138 000)
(7 428 000)
(7 724 000)
(8 049 000)
(8 356 000)
(8 654 000)
(9 219 000)
(9 525 000)
(9 864 000)
(10 187 000)






















(33 028 000)
(33 698 000)
(34 416 000)
(35 166 000)
(35 892 000)
(36 593 000)
(38 327 000)
(39 053 000)
(39 860 000)
(40 594 000)
(43 602 000)
(44 312 000)
(45 086 000)
(45 804 000)
(52 111 000)
(52 983 000)
(55 193 000)
(56 056 000)
(86 108 000)
(87 672 000)
(89 342 000)
(91 125 000)
(92 818 000)
(94 439 000)
(99 384 000)
(101 126 000)
(103 045 000)
(104 804 000)
(109 740 000)
(111 256 000)
(112 901 000)
(114 442 000)
(133 783 000)
(135 727 000)
(139 590 000)
(141 389 000)
(278 173 000)
(282 221 000)
(286 738 000)
(290 852 000)
(362 320 000)
(368 482 000)
(375 838 000)

(1 474 647 000)
(1 498 860 000)

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