A COMPILATION OF ENERGY-LEVELS AND WAVELENGTHS FOR THE SPECTRUM OF NEUTRAL BERYLLIUM (BE-I)

In this compilation we have used data from some 20 references, only tw o of which were available to C. E. Moore for her 1949 Atomic Energy Le vels tables. The new compilation thus includes significant revisions, extensions, and improvements of the earlier data for configurations of the types 1s(2)2snl and 1s(2)2pnl and also extends the energy range t o higher configurations, including those involving Is electron excitat ion. The observed wavelengths for some 200 lines are given with their energy-level classifications. The wavelength measurements, which exten d from 89 to 31 780 Angstrom, were obtained from emission spectra of h ollow-cathode and are discharges, beam-foil spectra, and far-ultraviol et photoabsorption spectra. In addition to the energy levels derived f rom these spectra, we include levels obtained from multiphoton resonan ce-ionization mass spectrometry and projectile-Auger spectroscopy. We have evaluated a number of levels by using series formulas and/or theo retical results; these levels are more accurate than values derived fr om available wavelength measurements. Wavelengths calculated from ener gy-level differences are given for all lines; these ''Ritz'' wavelengt hs are more accurate than the observed values wherever the differences are significant. (C) 1997 American Institute of Physics and American Chemical Society.