Lawrencium (Lr, Z = 103): atomic energy levels
No energy level diagram can be drawn for neutral lawrencium: no excited level of the atom has been measured, so there is no observed transition to show. This page lists what is known instead, and marks every calculated number as theory.
What has been measured
The first ionisation potential, by surface ionisation of 256Lr atoms one at a time (4.96 +0.05/-0.04 eV), and a lower limit of 13.0 eV for the second ionisation potential from a charge-exchange reaction (second-hand, Kwarsick et al., cited by Rickert et al.). A laser search at GSI (two-step resonance ionisation of 255Lr, about 1500 cm-1 scanned in total around the transitions predicted near 20 300 and 28 600 cm-1) found no atomic transition.
| Quantity | Value | Source |
|---|---|---|
| Ground configuration | [Rn] 5f14 7s2 7p theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Lr I (also data/nist/Lr_I_levels.tsv) |
| Ground term | 2P°1/2 theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Lr I |
| First ionisation energy | 4.96 +0.05 / −0.04 eV measured | T.K. Sato et al., J. Am. Chem. Soc. 140, 14609 (2018), p. 14611 Table 2 and text (weighted average of the 2015 and 2018 surface-ionisation measurements of 256Lr) |
| Longest-lived isotope | 266Lr, half-life 22 ± 14 h | NUBASE2020: F.G. Kondev, M. Wang, W.J. Huang, S. Naimi, G. Audi, Chin. Phys. C 45, 030001 (2021), machine-readable table nubase_4.mas20.txt, line for 266Lr |
Calculated transitions from the ground state
Theory only: none of these lines has been observed. Wavelengths are converted from the calculated level energies.
| Lower level | Upper level | Energy (cm⁻¹) | λ vacuum (nm) | Type | A (s⁻¹) theory | Source |
|---|---|---|---|---|---|---|
| 7s2 7p 2P*1/2 (ground) | 7s2 7d 2D3/2 | 28580 | 349.9 | E1 | 6.14e+07 | E.V. Kahl, S. Raeder, E. Eliav, A. Borschevsky, J.C. Berengut, Phys. Rev. A 104, 052810 (2021), arXiv:2103.11287v2, arXiv p. 7 Table IV and p. 13 Table VIII |
| 7s2 7p 2P*1/2 (ground) | 7s2 8s 2S1/2 | 20485 | 488.2 | E1 | 3.31e+07 | E.V. Kahl, S. Raeder, E. Eliav, A. Borschevsky, J.C. Berengut, Phys. Rev. A 104, 052810 (2021), arXiv:2103.11287v2, arXiv p. 7 Table IV and p. 12 Table VIII |
| 7s2 7p 2P*1/2 (ground) | 7s 7p2 4P1/2 | 25381 | 394.0 | E1 | 2.51e+07 | E.V. Kahl, S. Raeder, E. Eliav, A. Borschevsky, J.C. Berengut, Phys. Rev. A 104, 052810 (2021), arXiv:2103.11287v2, arXiv p. 7 Table IV and p. 12 Table VIII |