Tellurium energy level diagram

Energy levels and transitions of neutral tellurium (Te I): the 47 strongest classified lines below 2 µm from the NIST Atomic Spectra Database and the 36 levels they connect, each line with its vacuum wavelength, frequency and, for 39 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 tellurium

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).

¹²⁵Te 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 tellurium

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 Te 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, 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.

Te energy levels

Te⁺ ionisation limit 72669.01 cm⁻¹ = 9.00981 eV (137.610 nm)

Sources

• Bengtsson, Berzinsh, Larsson, Svanberg, Z. Phys. D 23, 29 (1992), abstract and p. 30, Tab…
• Garpman, Lido, Rydberg, Svanberg, Z. Phys. 247, 238 (1971) (optical double resonance and …
• Garpman, Svanberg, Phys. Scr. 5, 213 (1972) (optical double resonance and level crossing …
• NIST ASD
• NIST ASD level energies
• R. Sifi, PhD thesis, Universite Paris-Sud / IPN Orsay (2007), 'Ionisation resonante par f…
• R. Sifi, PhD thesis, Universite Paris-Sud / IPN Orsay (2007), 'Ionisation resonante par f…
• Roederer, Lawler, Cowan, et al., Astrophys. J. Lett. 747, L8 (2012), arXiv:1202.2378, Tab…
• This site: Cowan-code HFR calculation of Te I with the parameters fitted to the NIST ener…
• Zerne, Berzinsh, Svanberg, Z. Phys. D 32, 31 (1994) (two-step pulsed-laser excitation of …
• Zerne, Berzinsh, Svanberg, Z. Phys. D 32, 31 (1994), abstract (p. 31) and p. 32 (first tw…
• Zerne, Berzinsh, Svanberg, Z. Phys. D 32, 31 (1994), abstract (p. 31) and p. 32: level ca…

Thin file: neutral Te has little modern precision spectroscopy in open sources. The three lifetimes come from an abstract (OSTI/ETDEWEB record of Z. Phys. D 32, 31), read through an automated page reader and not checked against the printed paper. NIST carries A values for six 5p4 - 5p3 6s lines (Ubelis & Berzinsh); nothing better was found. Abundances: NIST isotopic compositions (120Te 0.09(1) %, 130Te 34.08(62) %). Third pass (2026-10-02): added the 6s 3S1 and 6s 5S2 lifetimes, the a 5P1 lifetime (identified through the excitation wavelengths printed on p. 32 of Zerne et al.), 123,125Te hyperfine constants and the 214 nm isotope shifts of 120-136Te from the open PhD thesis of R. Sifi (HAL tel-00252001, saved as pdf/Te_Sifi_2007.pdf). In that thesis A is the ground-level constant and A' the 6s 3S1 constant; isotope shifts are nu(A) - nu(130). Extra fields beyond SCHEMA.md: oscillator_strength_abs, isotope_shift_note, lifetime_alternatives. Fourth pass (2026-10-02): the four 7p lifetimes of Zerne et al. 1994 (128(11), 99(8), 82(10), 124(8) ns) were read a second time, independently, in the abstract on the Lund University publication record (https://lup.lub.lu.se/record/2259787) and agree with the stored values; the printed pages 33-34 are still unread.

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