# atomic ionization potentials (neutral atom and +1 ion), CRC Handbook of Chemistry and Physics, 79th edition, 1998
13.59844 20.02
24.58741 54.41778
5.39172 75.64018
9.3227 18.21116
8.29803 25.15484 
11.26030 24.38332
14.53414 29.6013
13.61806 35.11730
17.42282 34.97082
21.5646 40.96328
5.13908 47.2864
7.64624 15.03528
5.98577 18.82856
8.15169 16.34585
10.48669 19.7694
10.36001 23.3379
12.96764 23.814
15.75962 27.62967
4.34066 31.63
6.11316 11.87172
6.5615 12.79967
6.8281 13.5755
6.7463 14.66
6.7665 16.4857
7.43402 15.63999
7.9024 16.1878
7.8810 17.083
7.6398 18.16884
7.72638 20.29240
9.3942 17.96440
5.99930 20.5142
7.8994 15.93462
9.7886 18.633
9.75238 21.19
11.81381 21.8
13.99961 24.35985
4.17713 27.285
5.6949 11.03013
6.2171 12.24
6.63390 13.13
6.75885 14.32
7.09243 16.16
7.28 15.26
7.36050 16.76
7.45890 18.08
8.3369 19.43
7.5763 21.49
8.9938 16.90832
5.78636 18.8698
7.3439 14.63225
8.6084 16.53051
9.0096 18.6
10.45126 19.1313
12.1298 21.20979
3.89390 23.15745
5.21170 10.00390
5.770 11.060
5.5387 10.85
5.464 10.55
5.5250 10.73
5.58 10.9
5.6436 11.07
5.6704 11.241
6.1501 12.09
5.8638 11.52
5.9389 11.67
6.0215 11.80
6.1077 11.93
6.18431 12.05
6.25416 12.1761
5.4259 13.9
6.82507 14.9