Subscription Type
Physics Laboratory at the National Institute of Standards and Technology (NIST)
Resource Types
Statistics and Data
The Atomic Spectra Database (ASD) contains data for radiative transitions and energy levels in atoms and atomic ions. Data are included for observed transitions of 99 elements and energy levels of 56 elements. ASD contains data on about 950 spectra from about 1 Å (Ångströms) to 200 µm (micrometers), with about 72,000 energy levels and 102,000 lines, 40,000 of which have transition probabilities listed. The most current NIST-evaluated data associated with each transition are integrated under a single listing. Energy level data are included for most spectra of H-Kr (Z=1-36), Mo (Z=42), plus up to the first five spectra of the lanthanide rare earths (Z=57-71). Classified lines with transition probabilities are included for most spectra of H-Ni (Z=1-28); output for these can be ordered by either multiplet (for a given spectrum) or wavelength. Also, prominent lines (unclassified) with wavelengths and relative intensities are included for up to the first five spectra of H-Es (Z=1-99). Some transition probabilities are listed for selected lines of Cu-Es (Z=29-99). Comprehensive wavelength lists of observed lines with relative intensities are incorporated for all spectra of Mg, Al, S, Sc, plus Be I, O II, and Ne I.