Rutherfordium (Rf, Z = 104): atomic energy levels
No energy level diagram can be drawn for neutral rutherfordium: 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 adsorption chromatography of volatile compounds.
| Quantity | Value | Source |
|---|---|---|
| Ground configuration | [Rn] 5f14 6d2 7s2 theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Rf I (also data/nist/Rf_I_levels.tsv) |
| Ground term | 3F2 theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Rf I |
| First ionisation energy | 6.02 ± 0.04 eV theory | NIST Atomic Spectra Database, Ground States and Ionization Energies table (retrieved 2026-10-02), row Rf I; V.A. Dzuba, M.S. Safronova, U.I. Safronova, A. Kramida, Phys. Rev. A 94, 042503 (2016), Table II (author manuscript) |
| Longest-lived isotope | 267Rf, half-life 2.5 ± 1.5 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 267Rf |
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 6d2 3F2 (ground) | 7s2 7p6d 3F*2 | 2737 | 3653.6 | E1 | – | S.O. Allehabi, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 104, 052811 (2021), arXiv:2109.13716v2, p. 5 Table III and p. 8 Table X |
| 7s2 6d2 3F2 (ground) | 7s2 7p6d 3D*1 | 8028 | 1245.6 | E1 | – | S.O. Allehabi, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 104, 052811 (2021), arXiv:2109.13716v2, p. 5 Table III and p. 8 Table X |
| 7s2 6d2 3F2 (ground) | 7s2 7p6d 3D*2 | 11235 | 890.1 | E1 | – | S.O. Allehabi, V.A. Dzuba, V.V. Flambaum, Phys. Rev. A 104, 052811 (2021), arXiv:2109.13716v2, p. 5 Table III and p. 8 Table X |