Osmium energy level diagram

Energy levels and transitions of neutral osmium (Os I): the 90 strongest classified lines below 2 µm from the NIST Atomic Spectra Database and the 40 levels they connect, each line with its vacuum wavelength, frequency and, for 90 of them, the reduced dipole matrix element derived from the NIST transition rate. Measured lifetimes, transition rates, hyperfine constants and isotope shifts from the literature are included, each with its citation.

Hover a line or a level to isolate it, click to keep it selected. Scroll to zoom, drag to move.

Download: diagram (PDF) diagram (SVG) transitions (CSV) levels (CSV) source code

Key transitions of osmium

λ, ν from NIST level energies unless a measured frequency for this isotope is available. A: measured value or NIST. Γ/2π: natural linewidth of the upper level, 1/(2πτ).

Closed and nearly closed transitions of osmium

A transition is closed when its upper level can decay only to the level it was excited from, so the atom keeps scattering photons. “closed”: among the levels NIST lists, no other level below the upper level has the opposite parity and |ΔJ| ≤ 1, so no other electric-dipole decay exists. Otherwise the leak is the sum of the branching ratios of the other decay lines of the upper level (or 1 − branching ratio where that of the line itself has been measured), and the number of photons is 1 / leak. “≥” and “≤”: at least one possible decay path has no listed rate, so the leak is a lower limit. These numbers are derived from the branching ratios, lifetimes and rates of this page, not measured as such; the tag names the weakest of the inputs, * marks theory and ≈ a model or semi-empirical calculation. Listed: lines that start on the ground level or on a metastable level and leak at most 10 %, unless more than three possible decay paths have no listed rate. Fine-structure levels only: hyperfine and Zeeman dark states and forbidden decays without a listed rate are not considered. Select a line in the diagram for the full list of its leak channels.

Listed Os transitions below 2 µm

Reduced dipole matrix elements follow the convention A = ω³|d|²/(3πε₀ħc³(2J′+1)), with J′ the upper level. Tags show where a number comes from: measured, NIST compilation, high-accuracy theory, or a model calculation.

Os energy levels

Os⁺ ionisation limit 68058.90 cm⁻¹ = 8.43823 eV (146.932 nm)

Sources

• Ivarsson, Andersen, Nordström, et al., Astron. Astrophys. 409, 1141 (2003) (branching fra…
• Ivarsson, Andersen, Nordström, et al., Astron. Astrophys. 409, 1141 (2003), as tabulated …
• Ivarsson, Andersen, Nordström, et al., Astron. Astrophys. 409, 1141 (2003), as tabulated …
• Kwiatkowski, Zimmermann, Biémont, Grevesse, Astron. Astrophys. 135, 59 (1984), as listed …
• Kwiatkowski, Zimmermann, Biémont, Grevesse, Astron. Astrophys. 135, 59 (1984), as tabulat…
• NIST ASD level energies
• Quinet, Palmeri, Biémont, Jorissen, Van Eck, Svanberg, Xu, Plez, Astron. Astrophys. 448, …
• Quinet, Palmeri, Biémont, Jorissen, Van Eck, Svanberg, Xu, Plez, Astron. Astrophys. 448, …

Level energies are the NIST ASD values (the papers use the same Van Kleef & Klinkenberg 1961 energies). Transitions: 129 lines of Quinet et al. 2006 Table 5 (16 upper levels) plus Kurucz-listed Kwiatkowski 1984 lines not in that table. Order of preference for A_s: (1) measured branching fraction x measured lifetime of Ivarsson et al. 2003 as quoted by Quinet et al. (method 'compilation'), (2) Kwiatkowski et al. 1984 log gf as listed by Kurucz (method 'compilation', converted with A = 0.66702 sigma^2 gf / (2J'+1), sigma in cm-1 from the NIST-equal level energies), (3) semi-empirical value of Quinet et al. (calculated branching fraction x measured lifetime, method 'theory'). All A_s are per-line Einstein coefficients, derived from the printed gA or log gf; no uncertainties are printed for individual lines. Wavelengths in labels are air wavelengths computed from the level energies. Isotope abundances are in percent; abundance_unc is the NIST uncertainty in percent.

Atoms with measured data

• Lithium-632 levels, 85 lines
• Lithium-732 levels, 85 lines
• Beryllium-917 levels, 26 lines
• Sodium-2336 levels, 106 lines
• Magnesium-2418 levels, 61 lines
• Magnesium-2518 levels, 61 lines
• Potassium-3934 levels, 84 lines
• Potassium-4034 levels, 84 lines
• Potassium-4134 levels, 84 lines
• Calcium-4035 levels, 61 lines
• Calcium-4335 levels, 61 lines
• Chromium-5256 levels, 87 lines
• Chromium-5356 levels, 87 lines
• Rubidium-8536 levels, 94 lines
• Rubidium-8736 levels, 94 lines
• Strontium-8440 levels, 70 lines
• Strontium-8640 levels, 70 lines
• Strontium-8740 levels, 70 lines
• Strontium-8840 levels, 70 lines
• Cadmium-11115 levels, 21 lines
• Cadmium-11315 levels, 21 lines
• Cadmium-11415 levels, 21 lines
• Caesium-13331 levels, 79 lines
• Barium-13744 levels, 89 lines
• Barium-13844 levels, 89 lines
• Dysprosium-16139 levels, 55 lines
• Dysprosium-16239 levels, 55 lines
• Dysprosium-16339 levels, 55 lines
• Dysprosium-16439 levels, 55 lines
• Erbium-16673 levels, 90 lines
• Erbium-16773 levels, 90 lines
• Erbium-16873 levels, 90 lines
• Thulium-16972 levels, 73 lines
• Ytterbium-17118 levels, 26 lines
• Ytterbium-17318 levels, 26 lines
• Ytterbium-17418 levels, 26 lines
• Mercury-19927 levels, 47 lines
• Mercury-20127 levels, 47 lines
• Mercury-20227 levels, 47 lines

All elements: periodic table