Average atomic weight: 55.845(2) u
| Isotope | Fraction | Atomic weight/u |
| 54 | 0.05845(35) | 53.93960899(53) |
| 56 | 0.91754(36) | 55.93493633(49) |
| 57 | 0.02119(10) | 56.93539284(49) |
| 58 | 0.00282(4) | 57.93327443(53) |
Atomic weights and isotopic compositions were obtained from NIST Database 144
Fe I (Fe-like): 955 levels, 91828 lines (E1: 30269 IC: 61436 M1: 35 E2: 88), transition probabilities for 90499 lines
Fe II (Mn-like): 1008 levels, 84229 lines (E1: 31585 IC: 51273 M1: 370 E2: 1001), transition probabilities for 6723 lines
Fe III (Cr-like): 595 levels, 41705 lines (E1: 9708 IC: 29267 M1: 1080 E2: 1650), transition probabilities for 39481 lines
Fe IV (V -like): 276 levels, 11240 lines (E1: 2916 IC: 5530 M1: 677 E2: 2117), transition probabilities for 3741 lines
Fe V (Ti-like): 331 levels, 13022 lines (E1: 4035 IC: 7404 M1: 355 E2: 1228), transition probabilities for 4492 lines
Fe VI (Sc-like): 248 levels, 3858 lines (E1: 1583 IC: 1788 M1: 122 E2: 365), transition probabilities for 1702 lines
Fe VII (Ca-like): 154 levels, 974 lines (E1: 483 IC: 422 M1: 19 E2: 50), transition probabilities for 540 lines
Fe VIII (K -like): 41 levels, 63 lines (E1: 51 IC: 11 M1: 1), transition probabilities for 52 lines
Fe IX (Ar-like): 34 levels, 178 lines (E1: 100 IC: 22 M1: 19 E2: 30 M2: 4 E3: 3), transition probabilities for 68 lines
Fe X (Cl-like): 58 levels, 328 lines (E1: 149 IC: 177 M1: 1 E2: 1), transition probabilities for 168 lines
Fe XI (S -like): 30 levels, 98 lines (E1: 46 IC: 40 M1: 5 E2: 7), transition probabilities for 82 lines
Fe XII (P -like): 46 levels, 183 lines (E1: 93 IC: 73 M1: 9 E2: 8), transition probabilities for 147 lines
Fe XIII (Si-like): 36 levels, 183 lines (E1: 77 IC: 94 M1: 5 E2: 7), transition probabilities for 117 lines
Fe XIV (Al-like): 40 levels, 259 lines (E1: 163 IC: 88 M1: 3 E2: 4 M2: 1), transition probabilities for 245 lines
Fe XV (Mg-like): 41 levels, 230 lines (E1: 132 IC: 93 M1: 2 E2: 2 M2: 1), transition probabilities for 189 lines
Fe XVI (Na-like): 77 levels, 492 lines (E1: 492), transition probabilities for 299 lines
Fe XVII (Ne-like): 66 levels, 460 lines (E1: 346 IC: 113 M2: 1), transition probabilities for 135 lines
Fe XVIII (F -like): 63 levels, 105 lines (E1: 86 IC: 17 M1: 1 E2: 1), transition probabilities for 60 lines
Fe XIX (O -like): 63 levels, 197 lines (E1: 136 IC: 50 M1: 5 E2: 6), transition probabilities for 78 lines
Fe XX (N -like): 55 levels, 258 lines (E1: 136 IC: 108 M1: 9 E2: 5), transition probabilities for 172 lines
Fe XXI (C -like): 39 levels, 197 lines (E1: 92 IC: 88 M1: 5 E2: 7 M2: 5), transition probabilities for 176 lines
Fe XXII (B -like): 57 levels, 508 lines (E1: 298 IC: 204 M1: 3 E2: 2 M2: 1), transition probabilities for 196 lines
Fe XXIII (Be-like): 72 levels, 846 lines (E1: 447 IC: 394 M1: 2 E2: 2 M2: 1), transition probabilities for 372 lines
Fe XXIV (Li-like): 43 levels, 316 lines (E1: 248 IC: 68), transition probabilities for 95 lines
Fe XXV (He-like): 25 levels, 99 lines (E1: 64 IC: 34 M1: 1), transition probabilities for 70 lines
Fe XXVI (H -like): 100 levels, 914 lines (E1: 914), transition probabilities for 914 lines
(Atomic Line List v3.00b5)
