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Elemental Data Index Version History

Example of how to reference this online database: (Replace year, month day with database access date.)

Zucker, M.A., Kishore, A.R., Sukumar, R., and Dragoset, R.A. (2015), Elemental Data Index (version 2.5). [Online] Available: [year, month day]. National Institute of Standards and Technology, Gaithersburg, MD.
Citation Form:  
Author/editor (Year), Title (edition). [Type of medium] Available: URL [Access date].


Version 2.5
January 2015
Atomic weights were updated. See the Atomic Weights and Isotopic Compositions of the Elements database.  
Version 2.4
December 2011
The Spectral Data for the Chandra X-Ray Observatory database has been discontinued; the contents of the Chandra database have been completely superseded by the NIST Atomic Spectra Database (ASD). Therefore, the links in this database (from elements Ne, Mg, Si, & S) to the Chandra database have been removed.
Version 2.3
July 2010
Atomic weights and ionization energies were added/updated for several elements. See the Atomic Weights and Isotopic Compositions of the Elements database and the Ground Levels and Ionization Energies for the Neutral Atoms database for details. Also, elements 1 - 118 are included in the database and the design of the graphical interface was modified.
Version 2.2
July 2005
Updated the links for the "Atomic Spectra Database" to access the new version, Version 3.0.
Version 2.1
August 2004
Added access to two new, online databases: "Energy Levels of Hydrogen and Deuterium" for H and "Potential Energy Surface Database of Group II Dimer Molecules" for Mg, Ca, Sr & Ba; and added access to "Electron-Impact Cross Sections for Ionization and Excitation" for Li, B, C, N, O, Al, Ga & In.
Version 2.0
July 2003
Added access to three new, online databases: "Handbook of Basic Atomic Spectroscopic Data" (Z = 1 to 99), "Spectral Data for the Chandra X-ray Observatory" (S, Si, Mg, Ne), & "X-ray Transition Energies" (Z = 10 to 100). Added access to "Radionuclide Half-Life Measurements" for P and Ru. Additionally, there were minor changes made to some of the values of the atomic weights and the ionization energies.
Version 1.2
August 2001
Activated elements Z = 105-112, 114, and 116; and added access to atomic masses for elements without isotopic abundance. (Access to atomic masses for elements with isotopic abundance was previously available.)
Version 1.1
May 2000
Minor interface improvements, better page layout.
Version 1.0
September 1999
Available online.


Created August 14, 2009, Updated December 20, 2021