Dubnium (Db, Z = 105): atomic energy levels
No energy level diagram can be drawn for neutral dubnium: 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
No atomic-physics measurement. Only chemistry with single atoms: liquid-phase studies of (oxo)halide complexes and gas-phase chromatography (the element was identified chemically by gas thermochromatography).
| Quantity | Value | Source |
|---|---|---|
| Ground configuration | [Rn] 5f14 6d3 7s2 theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Db I (also data/nist/Db_I_levels.tsv) |
| Ground term | 4F3/2 theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Db I |
| First ionisation energy | 6.8 ± 0.5 eV theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Db I |
| Longest-lived isotope | 268Db, half-life 29 ± 3 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 268Db |
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 |
|---|---|---|---|---|---|---|
| 6d3 7s2 4F3/2 (ground) | 6d3 7s7p 4D*1/2 (state 37) | 29832 | 335.2 | E1 | 5.97e+07 | B.G.C. Lackenby, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 98, 022518 (2018), arXiv:1804.08244v1, p. 5 Table II (energy) and p. 6 Table III (rate) |
| 6d3 7s2 4F3/2 (ground) | 6d2 7s2 7p 6F*3/2 (state 17) | 21811 | 458.5 | E1 | 7.85e+06 | B.G.C. Lackenby, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 98, 022518 (2018), arXiv:1804.08244v1, p. 5 Table II and p. 6 Table III |
| 6d3 7s2 4F3/2 (ground) | 6d2 7s2 7p 2S*1/2 (state 28) | 27479 | 363.9 | E1 | 6.83e+06 | B.G.C. Lackenby, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 98, 022518 (2018), arXiv:1804.08244v1, p. 5 Table II and p. 6 Table III |