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NIST Atomic Spectra Database
Ionization Energies Data

At (all spectra)
85 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) 
  75 150.8         
  [144 210]          
  [214 400]          
  [319 800]          
  [406 400]          
  (581 000)          
  (686 000)          
  (1 049 000)          
  (1 202 000)          
  (1 363 000)          
  (1 549 000)          
  (1 710 000)          
  (1 903 000)          
  (2 121 000)          
  (2 315 000)          
  (2 508 000)          
  (2 702 000)          
  (3 642 000)          
  (3 880 000)          
  (4 120 000)          
  (4 360 000)          
  (4 840 000)          
  (5 100 000)          
  (5 780 000)          
  (6 060 000)          
  (6 390 000)          
  (6 920 000)          
  (7 440 000)          
  (7 965 000)          
  (8 480 000)          
  (9 010 000)          
  (9 530 000)          
  (10 060 000)          
  (10 640 000)          
  (11 160 000)          
  (11 700 000)          
  (12 200 000)          
  (12 800 000)          
  (13 300 000)          
  (15 712 000)          
  (16 188 000)          
  (16 704 000)          
  (17 252 000)          
  (17 768 000)          
  (18 277 000)          
  (19 140 000)          
  (19 672 000)          
  (20 245 000)          
  (20 777 000)          
  (22 914 000)          
  (23 430 000)          
  (24 011 000)          
  (24 535 000)          
  (26 713 000)          
  (27 326 000)          
  (28 818 000)          
  [29 433 200]          
  (48 200 000)          
  (49 377 000)          
  (50 644 000)          
  (51 982 000)          
  (53 265 000)          
  (54 515 000)          
  (57 007 000)          
  (58 314 000)          
  (59 750 000)          
  (61 080 000)          
  (64 782 000)          
  (65 936 000)          
  (67 194 000)          
  (68 364 000)          
  (75 227 000)          
  (76 598 000)          
  (79 317 000)          
  (80 607 000)          
  (171 102 000)          
  (174 216 000)          
  (177 684 000)          
  (180 862 000)          
  (206 301 000)          
  (210 390 000)          
  (215 584 000)          
  (218 891 000)          
  (870 514 400)          
  (886 300 000)          
Notes:
a Uncertainty of the listed value is unknown.

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