Atomic energy level diagrams

Indium energy level diagram

Energy levels and transitions of neutral indium (In I): the 30 strongest classified lines below 2 µm from the NIST Atomic Spectra Database and the 21 levels they connect, each line with its vacuum wavelength, frequency and, for 30 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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Indium energy level diagram with transition wavelengths and dipole matrix elements

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

Key transitions of indium

Transitionλ vac (nm)λ air (nm)ν (THz)|⟨J‖er‖J′⟩| (ea₀)A (s⁻¹)Γ/2π up. (MHz)branch (%)Use
5s25p 2P°1/2 – 5s28s 2S1/2246.0813246.00681218.26600.2855.510e+063.00329.2246.0 nm line used for collinear resonance ionization spe…
5s25p 2P°3/2 – 5s29s 2S1/2246.8744246.79981214.35190.2785.210e+061.34961.5246.8 nm line used for collinear resonance ionization spe…
5s25p 2P°3/2 – 5s25d 2D5/2325.7017325.6078920.45103.6471.300e+0820.94100325.6 nm laser-cooling / MOT transition 5P3/2
5s25p 2P°1/2 – 5s26s 2S1/2410.2908410.1750730.68291.8394.960e+0722.7435.7410.2 nm resonance line
5s25p 2P°3/2 – 5s26s 2S1/2451.2562451.1297664.35082.8468.930e+0722.7464.3451.1 nm line
5s26s 2S1/2 – 5s26p 2P°3/21291.60691291.2536232.10818.172*1.570e+072.8941001291 nm second step of two-step spectroscopy
5s26s 2S1/2 – 5s26p 2P°1/21343.35931342.9920223.16635.850*1.430e+072.8941001343 nm second step of two-step spectroscopy

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).

115In hyperfine structure (I = 9/2)

LevelA (MHz)B (MHz)Shift of each F level from the centre of gravity (MHz)
5s25p 2P°1/22281.9501(4)–F=4: -6275.36 F=5: +5134.39
5s25p 2P°3/2242.1647(3)449.545(3)F=3: -1791.82 F=4: -1122.86 F=5: -5.69 F=6: +1747.00
5s26s 2S1/21685.3(6)–F=4: -4634.57 F=5: +3791.93
5s26p 2P°1/2251.40(10)–F=4: -691.35 F=5: +565.65
5s26p 2P°3/279.33(7)62.5(5)F=3: -625.83 F=4: -350.17 F=5: +33.46 F=6: +551.10
5s25d 2D3/2-64.0(10)41(20)F=3: +546.79 F=4: +263.46 F=5: -65.08 F=6: -421.75
5s25d 2D5/2151.2(9)33(20)F=2: -2063.88 F=3: -1620.17 F=4: -1024.72 F=5: -274.23 F=6: +635.45 F=7: +1709.25
5s27s 2S1/2541.0(3)–F=4: -1487.75 F=5: +1217.25
5s5p2 4P5/23696.0(10)-660(30)F=2: -51122.50 F=3: -39836.50 F=4: -24865.50 F=5: -6275.50 F=6: +15851.00 F=7: +41415.00
5s28s 2S1/2243.85(24)–F=4: -670.59 F=5: +548.66
5s29s 2S1/2131.1(10)–F=4: -360.44 F=5: +294.91

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

Isotope shifts

Transitionλ vac (nm)IsotopesShift (MHz)
5s25p 2P°1/2 – 5s28s 2S1/2246.081115-113268.0(20)
5s25p 2P°3/2 – 5s29s 2S1/2246.874115-113-270.0(20)
5s25p 2P°1/2 – 5s26s 2S1/2410.291115-113-260(3)
5s25p 2P°3/2 – 5s26s 2S1/2451.256113-115255.4(5)

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

Closed and nearly closed transitions of indium

Transitionλ vacuum (nm)Lower levelA (s⁻¹)Leak per scattered photonPhotons before a leakWhere the leak goes
5s25p 2P°3/2 → 5s25d 2D5/2325.7017metastable1.300e+08 NIST2 × 10−4 from theory5,0005s26p 2P°3/2 2 × 10−4*

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 In transitions below 2 µm

Lower levelUpper levelλ vacuum (nm)λ air (nm)ν (THz)Type|⟨J‖er‖J′⟩| (ea₀)A (s⁻¹)Branching (%)Source of matrix element / A
5s25p 2P°1/25s211s 2S1/2224.2361224.16651336.9503E10.113 NIST1.140e+06 NIST–NIST ASD (accuracy C+)
5s25p 2P°1/25s210s 2S1/2227.8877227.81741315.5271E10.145 NIST1.810e+06 NIST–NIST ASD (accuracy C+)
5s25p 2P°1/25s28d 2D3/2230.7554230.68441299.1785E10.0585 NIST1.410e+05 NIST4.47NIST ASD (accuracy C+)
5s25p 2P°1/25s29s 2S1/2234.0878234.01601280.6840E10.196 NIST3.040e+06 NIST35.9NIST ASD (accuracy C+)
5s25p 2P°3/25s211s 2S1/2235.9422235.87011270.6182E10.161 NIST2.010e+06 NIST–NIST ASD (accuracy C+)
5s25p 2P°1/25s27d 2D3/2239.0262238.95341254.2240E10.284 NIST2.990e+06 NIST59.8NIST ASD (accuracy C+)
5s25p 2P°3/25s210s 2S1/2239.9885239.91551249.1950E10.210 NIST3.220e+06 NIST–NIST ASD (accuracy C+)
5s25p 2P°3/25s28d 2D5/2243.0578242.98401233.4206E10.182 NIST7.830e+05 NIST18.6NIST ASD (accuracy C+)
5s25p 2P°3/25s28d 2D3/2243.1710243.09721232.8465E10.202 theory1.430e+06 theory45.3Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table II (all-order SD)
5s25p 2P°1/25s28s 2S1/2246.0813246.00681218.2660E10.285 NIST5.510e+06 NIST29.2NIST ASD (accuracy C+)
5s25p 2P°3/25s29s 2S1/2246.8744246.79981214.3519E10.278 NIST5.210e+06 NIST61.5NIST ASD (accuracy C+)
5s25p 2P°3/25s27d 2D5/2252.2109252.13501188.6579E10.503 NIST5.330e+06 NIST78.3NIST ASD (accuracy C+)
5s25p 2P°3/25s27d 2D3/2252.3735252.29761187.8920E10.201 NIST1.270e+06 NIST25.4NIST ASD (accuracy C+)
5s25p 2P°1/25s26d 2D3/2256.0916256.01481170.6455E10.808 NIST1.970e+07 NIST41.4NIST ASD (accuracy B)
5s25p 2P°3/25s28s 2S1/2260.2514260.17371151.9340E10.414 NIST9.850e+06 NIST52.2NIST ASD (accuracy C+)
5s25p 2P°3/25s26d 2D5/2271.1072271.02681105.8079E11.267 NIST2.720e+07 NIST50.6NIST ASD (accuracy B)
5s25p 2P°3/25s26d 2D3/2271.4741271.39361104.3134E10.428 NIST4.630e+06 NIST9.72NIST ASD (accuracy C+)
5s25p 2P°1/25s27s 2S1/2275.4679275.38651088.3025E10.518 NIST1.300e+07 NIST25.4NIST ASD (accuracy B)
5s25p 2P°1/25s5p2 4P3/2277.6175277.53561079.8758E1 (intercombination)0.105 NIST2.600e+05 NIST–NIST ASD (accuracy C+)
5s25p 2P°3/25s5p2 4P5/2283.7736283.69011056.4495E1 (intercombination)0.0991 NIST1.450e+05 NIST–NIST ASD (accuracy C+)
5s25p 2P°1/25s5p2 4P1/2285.8966285.81271048.6044E1 (intercombination)0.123 NIST6.530e+05 NIST–NIST ASD (accuracy C+)
5s25p 2P°3/25s27s 2S1/2293.3475293.26171021.9705E10.755 NIST2.290e+07 NIST44.7NIST ASD (accuracy B)
5s25p 2P°3/25s5p2 4P3/2295.7864295.70001013.5438E1 (intercombination)0.132 NIST3.430e+05 NIST–NIST ASD (accuracy C+)
5s25p 2P°1/25s25d 2D3/2304.0232303.9347986.0842E12.482 NIST1.110e+08 NIST84NIST ASD (accuracy B+)
5s25p 2P°3/25s25d 2D5/2325.7017325.6078920.4510E13.647 NIST1.300e+08 NIST100NIST ASD (accuracy B+)
5s25p 2P°3/25s25d 2D3/2325.9492325.8552919.7522E11.432 NIST3.000e+07 NIST16NIST ASD (accuracy B)
5s25p 2P°1/25s26s 2S1/2410.2908410.1750730.6829E11.839 NIST4.960e+07 NIST35.7NIST ASD (accuracy B+)
5s25p 2P°3/25s26s 2S1/2451.2562451.1297664.3508E12.846 NIST8.930e+07 NIST64.3NIST ASD (accuracy B+)
5s26s 2S1/25s26p 2P°3/21291.60691291.2536232.1081E18.172 theory1.570e+07 theory100Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table II (all-order SD)
5s26s 2S1/25s26p 2P°1/21343.35931342.9920223.1663E15.850 theory1.430e+07 theory100Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table II (all-order SD)

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, this site's own Cowan-code calculation with the parameters fitted to the NIST energies (HFR fit; inputs and fit report in the repository folder cowan/; used only where nothing else gives a rate; strong lines typically within a factor 2, weak lines worse), or a model calculation.

In energy levels

LevelEnergy (cm⁻¹)JParityLifetimegJHyperfine A (MHz)Hyperfine B (MHz)Lifetime sourceHyperfine source
5s25p 2P°1/20.0001/2oddstable–2281.95––Garcia Ruiz et al., Phys. Rev. X 8, 041005 (2018), Table I, literature column; original: …
5s25p 2P°3/22212.5993/2odd10.4 s theory–242.165449.545Sahoo, Das, Phys. Rev. A 84, 012501 (2011) (arXiv:1102.2496), Table III, recommended valu…Garcia Ruiz et al., Phys. Rev. X 8, 041005 (2018), Table I, literature column; original: …
5s26s 2S1/224372.9571/2even7 ns measured–1685.3–Norton, Gallagher, Phys. Rev. A 3, 915 (1971) (abstract; Hanle effect)Garcia Ruiz et al., Phys. Rev. X 8, 041005 (2018), Table I, literature column, attributed…
5s26p 2P°1/231816.9821/2odd55 ns measured–251.4–Sahoo, Das, Phys. Rev. A 84, 012501 (2011) (arXiv:1102.2496), Table III, column Expt; ori…Augenbraun, Carter, Rupasinghe, Majumder, Phys. Rev. A 94, 022515 (2016) (arXiv:1607.0179…
5s26p 2P°3/232115.2513/2odd55 ns measured–79.3362.5Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI (55.0 +- 4) and Sa…Gunawardena, Cao, Hess, Majumder, Phys. Rev. A 80, 032519 (2009) (abstract): a = 79.33(7)…
5s25d 2D3/232892.2303/2even6.3 ns measured–-6441Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Anderse…Vernon et al., arXiv:2005.06051 (2020), "Laser spectroscopy of indium Rydberg atom bunche…
5s25d 2D5/232915.5395/2even7.6 ns measured–151.233Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Anderse…Vernon et al., arXiv:2005.06051 (2020), "Laser spectroscopy of indium Rydberg atom bunche…
5s5p2 4P1/234977.6781/2even––––––
5s5p2 4P3/236020.7803/2even––––––
5s27s 2S1/236301.8641/2even19.5 ns measured–541–Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Zaki Ew…Garcia Ruiz et al., Phys. Rev. X 8, 041005 (2018), Table I, literature; original: George,…
5s5p2 4P5/237451.9625/2even––3696-660–Garcia Ruiz et al., Phys. Rev. X 8, 041005 (2018), Table I, this work
5s26d 2D3/239048.5303/2even21 ns measured–––Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Anderse…–
5s26d 2D5/239098.3805/2even18.6 ns measured–––Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Zaki Ew…–
5s28s 2S1/240636.9801/2even53 ns measured–243.85–Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Zaki Ew…Garcia Ruiz et al., Phys. Rev. X 8, 041005 (2018), Table I, this work
5s27d 2D3/241836.4103/2even200 ns measured–––Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Jonsson…–
5s27d 2D5/241861.9605/2even147 ns measured–––Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Jonsson…–
5s29s 2S1/242719.0201/2even118 ns measured–131.07–Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Zaki Ew…Garcia Ruiz et al., Phys. Rev. X 8, 041005 (2018), Table I, this work
5s28d 2D3/243335.9303/2even317 ns measured–––Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Zaki Ew…–
5s28d 2D5/243355.0805/2even238 ns measured–––Safronova, Safronova, Kozlov, Phys. Rev. A 76, 022501 (2007), Table VI; original: Jonsson…–
5s210s 2S1/243881.2601/2even––––––
5s211s 2S1/244595.8601/2even––––––

In⁺ ionisation limit 46670.11 cm⁻¹ = 5.78636 eV (214.270 nm)

Sources

Both stable isotopes have I = 9/2 (115In is very weakly radioactive, 95.71%). Hyperfine entries from Garcia Ruiz et al. 2018 carry statistical (A_unc) and systematic (A_unc_sys) uncertainties separately. level_isotope_shift_MHz is the shift of the level itself (113In minus 115In centroid, relative to the ionization limit) as tabulated by Sahoo et al. 2019 / Vernon et al. 2020. Transition isotope shifts keep the printed convention: keys "115-113" mean nu(115)-nu(113). rme_J_ea0 values are theory unless noted: "CC" = linearized coupled-cluster (Safronova, Safronova, Porsev 2013), sqrt(S) values derived from the all-order SD line strengths of Safronova, Safronova, Kozlov 2007 (same convention as the schema: A = 2.02613e18 S/((2J'+1) lambda^3)). The 6s-6p matrix elements and 6p lifetimes marked derived come from the measured 410 nm Stark shift (Ranjit et al. 2013) plus theory. Extra fields beyond SCHEMA.md: level_isotope_shift_MHz, natural_linewidth_MHz, stark_shift_kHz_per_kVcm2, C_MHz (magnetic octupole), *_unc_sys, ionization_energy, mu_N. The UDel portal has no neutral In entry (only In+).

Atoms with measured data

All elements: periodic table