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National Institute of Standards and Technology
Gaithersburg, Maryland 20899
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Note
for Macintosh Users: Due to differences in many Macintosh browsers, the
spectroscopic notation of this article may appear with unintended spacing on a
Macİ. A PDF version (705 kB) of this
article may be used instead. The table of Ground levels and ionization
energies for the neutral atoms (PDF 106 kB) is also
available.