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NIST Atomic Spectra Database
Ionization Energies Data

Th (all spectra)
90 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) 
  50 867          
  97 600          
  [147 800]         
  231 065          
  (468 000)         
  (557 000)         
  (661 000)         
  (766 000)         
  (952 000)         
  (1 073 000)         
  (1 331 000)         
  (1 460 000)         
  (2 113 000)         
  (2 299 000)         
  (2 500 000)         
  (2 710 000)         
  (2 920 000)         
  (3 137 000)         
  (3 420 000)         
  (3 638 000)         
  (3 871 000)         
  (4 097 000)         
  (5 234 000)         
  (5 506 000)         
  (5 778 000)         
  (6 049 000)         
  (6 700 000)         
  (7 000 000)         
  (7 810 000)         
  (8 120 000)         
  (8 790 000)         
  (9 380 000)         
  (9 970 000)         
  (10 558 000)         
  (11 150 000)         
  (11 740 000)         
  (12 320 000)         
  (12 910 000)         
  (13 580 000)         
  (14 180 000)         
  (14 780 000)         
  (15 400 000)         
  (16 000 000)         
  (16 600 000)         
  (19 277 000)         
  (19 801 000)         
  (20 357 000)         
  (20 954 000)         
  (21 527 000)         
  (22 075 000)         
  (23 100 000)         
  (23 672 000)         
  (24 301 000)         
  (24 890 000)         
  (27 221 000)         
  (27 786 000)         
  (28 407 000)         
  (28 980 000)         
  (31 802 000)         
  (32 464 000)         
  (34 117 000)         
  [34 782 800]         
  (56 233 000)         
  (57 507 000)         
  (58 870 000)         
  (60 314 000)         
  (61 685 000)         
  (63 032 000)         
  (65 968 000)         
  (67 371 000)         
  (68 928 000)         
  (70 348 000)         
  (74 340 000)         
  (75 574 000)         
  (76 921 000)         
  (78 179 000)         
  (87 003 000)         
  (88 495 000)         
  (91 463 000)         
  (92 867 000)         
  (194 097 000)         
  (197 428 000)         
  (201 130 000)         
  (204 534 000)         
  (237 224 000)         
  (241 708 000)         
  (247 427 000)         
  (251 022 000)         
  (992 796 200)         
  (1 010 212 000)         
Notes:
a Uncertainty of the listed value is unknown.

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

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