Energy level diagrams of the elements

Pick an element to open its interactive Grotrian diagram: every drawn transition carries its vacuum wavelength and reduced dipole matrix element, and pointing at a line isolates it and shows frequency, Einstein coefficient and source.

Find an element

Alkali metal
Alkaline earth
Transition metal
Post-transition metal
Metalloid
Nonmetal
Noble gas
Lanthanide
Actinide
Measured lifetimes, hyperfine data and isotope shifts included

1HHydrogen74 lines 2HeHelium79 lines 3LiLithium85 lines 4BeBeryllium26 lines 5BBoron45 lines 6CCarbon80 lines 7NNitrogen96 lines 8OOxygen79 lines 9FFluorine46 lines 10NeNeon74 lines 11NaSodium106 lines 12MgMagnesium61 lines 13AlAluminium45 lines 14SiSilicon79 lines 15PPhosphorus50 lines 16SSulfur81 lines 17ClChlorine79 lines 18ArArgon75 lines 19KPotassium84 lines 20CaCalcium61 lines 21ScScandium90 lines 22TiTitanium88 lines 23VVanadium90 lines 24CrChromium87 lines 25MnManganese90 lines 26FeIron71 lines 27CoCobalt70 lines 28NiNickel70 lines 29CuCopper31 lines 30ZnZinc70 lines 31GaGallium25 lines 32GeGermanium54 lines 33AsArsenic64 lines 34SeSelenium16 lines 35BrBromine47 lines 36KrKrypton84 lines 37RbRubidium94 lines 38SrStrontium70 lines 39YYttrium90 lines 40ZrZirconium90 lines 41NbNiobium90 lines 42MoMolybdenum90 lines 43TcTechnetium70 lines 44RuRuthenium90 lines 45RhRhodium48 lines 46PdPalladium46 lines 47AgSilver62 lines 48CdCadmium21 lines 49InIndium30 lines 50SnTin51 lines 51SbAntimony82 lines 52TeTellurium47 lines 53IIodine50 lines 54XeXenon72 lines 55CsCaesium79 lines 56BaBarium89 lines 57LaLanthanum90 lines 58CeCerium90 lines 59PrPraseodymium74 lines 60NdNeodymium18 lines 61PmPromethium18 lines 62SmSamarium90 lines 63EuEuropium90 lines 64GdGadolinium60 lines 65TbTerbium13 lines 66DyDysprosium55 lines 67HoHolmium39 lines 68ErErbium90 lines 69TmThulium73 lines 70YbYtterbium26 lines 71LuLutetium66 lines 72HfHafnium74 lines 73TaTantalum90 lines 74WTungsten90 lines 75ReRhenium90 lines 76OsOsmium90 lines 77IrIridium53 lines 78PtPlatinum79 lines 79AuGold23 lines 80HgMercury47 lines 81TlThallium18 lines 82PbLead31 lines 83BiBismuth39 lines 84PoPolonium4 lines 85AtAstatine2 lines 86RnRadon10 lines 87FrFrancium77 lines 88RaRadium22 lines 89AcActinium72 lines 90ThThorium71 lines 91PaProtactinium64 lines 92UUranium90 lines 93NpNeptunium90 lines 94PuPlutonium85 lines 95AmAmericium21 lines 96CmCurium88 lines 97BkBerkelium86 lines 98CfCalifornium65 lines 99EsEinsteinium12 lines 100FmFermium7 lines 101MdMendeleviumno spectrum 102NoNobelium1 lines 103LrLawrenciumno spectrum 104RfRutherfordiumno spectrum 105DbDubniumno spectrum 106SgSeaborgiumno spectrum 107BhBohriumno spectrum 108HsHassiumno spectrum 109MtMeitneriumno spectrum 110DsDarmstadtiumno spectrum 111RgRoentgeniumno spectrum 112CnCoperniciumno spectrum 113NhNihoniumno spectrum 114FlFleroviumno spectrum 115McMoscoviumno spectrum 116LvLivermoriumno spectrum 117TsTennessineno spectrum 118OgOganessonno spectrum

57–71

89–103

Atoms with measured data

For the atoms that cold-atom, optical-tweezer, optical-clock and ion-trap experiments work with, each isotope has its own page. Beyond the NIST level energies these include measured lifetimes, transition rates, hyperfine constants and isotope shifts, each with its citation; calculated values are tagged as such.

What each page contains

A zoomable diagram (also as PDF and SVG), a table of the key or strongest transitions, the transition list with wavelengths in vacuum and air, frequencies, dipole matrix elements and Einstein A coefficients, and the level energies. Level energies and most transition rates come from the NIST Atomic Spectra Database; for the actinides from protactinium onwards, where NIST lists only the ground level, they come from the literature cited on the page. For mendelevium, lawrencium and the elements from rutherfordium on, no excited level has ever been measured: their cells (dashed) open a short page with the ground state, the ionisation energy and calculated lines, marked as theory. All tables are downloadable as CSV from the GitHub repository.