[skip navigation]
[ASD Home][Lines Query][Levels Query][List of Spectra][Ground States and Ionization Energies][Bibliography][Help] NIST Physical Measurement Laboratory
National Institute of Standards and Technology NIST Physical Measurement Laboratory
NIST Atomic Spectra Database
Ionization Energies Data

Re (all spectra)
75 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) 
  63 181.6         
  [134 000]          
  (218 000)          
  (315 000)          
  (419 000)          
  (540 000)          
  [667 100]          
  [1 165 000]          
  (1 329 000)          
  (1 505 000)          
  (1 681 000)          
  (1 903 000)          
  (2 160 000)          
  (2 350 000)          
  (2 660 000)          
  (3 040 000)          
  (3 250 000)          
  (3 460 000)          
  (3 842 000)          
  (4 220 000)          
  (4 600 000)          
  (4 990 000)          
  (5 370 000)          
  (5 770 000)          
  (6 160 000)          
  (6 540 000)          
  (6 920 000)          
  (7 310 000)          
  (7 690 000)          
  (9 630 000)          
  (10 017 000)          
  (10 437 000)          
  (10 880 000)          
  (11 308 000)          
  (11 727 000)          
  (12 340 000)          
  (12 768 000)          
  (13 236 000)          
  (13 679 000)          
  (15 421 000)          
  (15 857 000)          
  (16 333 000)          
  (16 776 000)          
  (18 067 000)          
  (18 567 000)          
  (19 761 000)          
  [20 281 100]          
  33 985 000           
  (34 964 000)          
  (36 037 000)          
  (37 174 000)          
  (38 271 000)          
  (39 336 000)          
  (41 126 000)          
  (42 231 000)          
  (43 457 000)          
  (44 586 000)          
  (47 740 000)          
  (48 732 000)          
  (49 813 000)          
  (50 813 000)          
  (54 926 000)          
  (56 072 000)          
  (58 314 000)          
  (59 411 000)          
  (129 662 000)          
  (132 364 000)          
  (135 348 000)          
  (138 106 000)          
  (153 278 000)          
  (156 657 000)          
  (160 932 000)          
  (163 709 600)          
  (657 798 200)          
  (670 750 100)          
Notes:
a Uncertainty of the listed value is unknown.

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

[ASD Home][Lines Query][Levels Query][List of Spectra][Ground States and Ionization Energies][Bibliography][Help] NIST Physical Measurement Laboratory