Cerium energy level diagram

Energy levels and transitions of neutral cerium (Ce I): the 90 strongest classified lines below 2 µm from the NIST Atomic Spectra Database and the 67 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.

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

Strongest transitions of cerium

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).

Listed Ce 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.

Ce energy levels

Ce⁺ ionisation limit 44672.00 cm⁻¹ = 5.53862 eV (223.854 nm)

Sources

• Curry, J. Phys. D: Appl. Phys. 42, 135205 (2009), Table 1
• Den Hartog, Buettner, Lawler, J. Phys. B 42, 085006 (2009), Table 1 (pp. 4-6; time-resolv…
• Lawler, Chisholm, Nitz, Wood, Sobeck, Den Hartog, J. Phys. B 43, 085701 (2010), Table 3 (…
• NIST ASD
• NIST ASD level energies
• branching ratio / lifetime

Level lifetimes: all 153 levels of Den Hartog, Buettner, Lawler, J. Phys. B 42, 085006 (2009), Table 1 (PDF saved as pdf/Ce_DenHartog_2009.pdf; bronze open access on the publisher site), parsed from the PDF text and matched to NIST level energies and J (all 153 matched within 0.002 cm-1; the 25384.989 level has J "3 or 4 or 5"). The paper states one common uncertainty of ±5 % (which the authors call closer to two sigma); unc = 5 % of the value. The values of Bisson 1991, Li 2000 and Xu 2003 printed in the "Other" column are stored as "alternatives" with method "compilation"; Den Hartog et al. find the Bisson lifetimes systematically longer (mean -35.5 %). Transitions: (a) 32 lines between drawn levels for which NIST gives no A, from Curry 2009 (semi-empirical arc-intensity values, ±35 %, likely biased high, see conflicts); (b) the 5 printed stub rows of Table 3 of Lawler et al. 2010 (PDF pdf/Ce_Lawler_2010.pdf) with A and uncertainty as printed; (c) the 24 branching fractions of the 19661.076 cm-1 (J=5) level from Table 2 of Lawler et al. 2010 - the table lists 24 of the 43 detected branches and the fractions sum to 0.904; no A is stored for these (it would be fraction/lifetime, a derived number; e.g. the 607.2 nm branch 0.16273/47.1 ns reproduces the NIST value 3.45e6 s-1, so NIST reference T8748 is this paper). Sanity check: lifetime x (sum of NIST A plus the Curry/Lawler A entered here) is at most 0.97 for the 51 levels that have both. The stable Ce isotopes have nuclear s

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