Platinum energy level diagram

Energy levels and transitions of neutral platinum (Pt I): the 79 strongest classified lines below 2 µm from the NIST Atomic Spectra Database and the 43 levels they connect, each line with its vacuum wavelength, frequency and, for 73 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 platinum

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).

¹⁹⁵Pt hyperfine structure (I = 1/2)

Measured A, B constants; sources in the data file.

Isotope shifts

Shift = ν(first isotope) − ν(second isotope).

Closed and nearly closed transitions of platinum

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 Pt 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.

Pt energy levels

Pt⁺ ionisation limit 72257.80 cm⁻¹ = 8.95883 eV (138.393 nm)

Sources

• Atomic-beam magnetic-resonance value quoted as 'Ref. 12' in Table 2 of LaBelle, Fairbank,…
• Atomic-beam magnetic-resonance value quoted as 'Ref. 13' in Table 2 of LaBelle, Fairbank,…
• Büttgenbach, Glaeser, Roski, Träber, Z. Phys. A 317, 237 (1984), as quoted in Hirayama et…
• Den Hartog, Herd, Lawler, Sneden, Cowan, Beers, Astrophys. J. 619, 639 (2005), Table 1 (p…
• Den Hartog, Herd, Lawler, Sneden, Cowan, Beers, Astrophys. J. 619, 639 (2005), Table 1 (p…
• Gough, Hannaford, Lowe, J. Phys. B 15, L431 (1982), as listed in R. L. Kurucz, gf7800.all…
• H. Grethen, diploma work, Berlin 1976 (unpublished; reference [40], footnote a), as quote…
• Hirayama et al., 'In-gas-cell laser spectroscopy for magnetic dipole moment of 199Pt towa…
• LaBelle, Fairbank, Engleman, Keller, J. Opt. Soc. Am. B 6, 137 (1989), Table 2 and abstra…
• Müller, Winkler, Z. Phys. A 273, 313 (1975), re-evaluated by Neu, Passler, Sawatzky, Wink…
• NIST ASD
• NIST ASD level energies
• Neu, Passler, Sawatzky, Winkler, Kluge, 'Isotope shift and hyperfine structure of stable …

NIST ASD already carries A values for 166 Pt I lines; of the 58 measured lines (Gough-Hannaford-Lowe 1982, Lotrian-Guern 1982) in the Kurucz list gf7800.all only 3 are missing from NIST and those are added here (derived from log gf with A = 0.66702 sigma^2 gf / (2J'+1)). Isotope shifts are nu(first) - nu(second); for the 248.792 nm line the heavier isotope lies at higher frequency. The 199Pt-198Pt shift on the same line is 0.98(48) GHz (199Pt is radioactive, not listed under isotopes). 195Pt has I = 1/2: hyperfine entries have A only. Isotope abundances in percent; abundance_unc in percent. Second pass (2026-10-02): 58 odd-level lifetimes from Den Hartog et al., Astrophys. J. 619, 639 (2005), Table 1 (levels there carry the Blaise et al. 1992 energies, matched to the NIST levels within 0.04 cm^-1 (most within 0.02) and by J). Where Table 2 prints an explicit uncertainty it is used; otherwise the uncertainty is the paper's stated rule 'larger of 5 % or 0.2 ns'. The NIST A values of Pt I already come from this paper's Table 3, so no transition rates were added. Third pass (2026-10-02): 195Pt hyperfine constants of 14 levels, isotope shifts of 11 lines and four g_J values from (a) the scanned CERN preprint of Neu et al. 1987 (pages read as images, Table 1 and Table 2 each read twice at two resolutions) and (b) the tables of LaBelle et al. 1989 embedded in Wayback copies of the Optica abstract page (parsed from the HTML, two captures identical). All were printed in mK (10^-3 cm^-

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