Hassium (Hs, Z = 108): atomic energy levels
No energy level diagram can be drawn for neutral hassium: 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 gas-phase adsorption chromatography of a volatile compound with single atoms (Steinegger 2021 names Mt, Ds and Rg as the only superheavy elements up to Fl without any chemical study; the specific Hs compound was not read in a source opened here).
| Quantity | Value | Source |
|---|---|---|
| Ground configuration | [Rn] 5f14 6d6 7s2 theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Hs I (also data/nist/Hs_I_levels.tsv) |
| Ground term | 5D4 theory | B.G.C. Lackenby, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 99, 042509 (2019), arXiv:1902.06819v2, p. 12-13 Tables III-IV; NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02) |
| First ionisation energy | 7.6 ± 0.5 eV theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Hs I |
| Longest-lived isotope | 269Hs, half-life 15 ± 7 s | 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 269Hs |
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 |
|---|---|---|---|---|---|---|
| 6d6 7s2 5D4 (ground) | 6d5 7s2 7p, J=3 odd (state 35) | 39652 | 252.2 | E1 | 8e+07 | B.G.C. Lackenby, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 99, 042509 (2019), arXiv:1902.06819v2, p. 12-13 Tables III-IV (energy) and p. 14 Table V (rate) |
| 6d6 7s2 5D4 (ground) | 6d5 7s2 7p, J=5 odd (state 33) | 39268 | 254.7 | E1 | 7.75e+07 | B.G.C. Lackenby, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 99, 042509 (2019), arXiv:1902.06819v2, p. 12-13 Tables III-IV (energy) and p. 14 Table V (rate) |
| 6d6 7s2 5D4 (ground) | 6d5 7s2 7p, J=3 odd (state 24) | 34812 | 287.3 | E1 | 3.55e+07 | B.G.C. Lackenby, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 99, 042509 (2019), arXiv:1902.06819v2, p. 12-13 Tables III-IV (energy) and p. 14 Table V (rate) |