Romuald Zalubas

Energy levels of magnesium, Mg I through Mg XII

Energy level data are given for the atom and all positive ions of magnesium (Z=12). These data have been critically compiled, mainly from published material on measurements and analyses of the optical spectra. We have derived or recalculated the levels for a number of the ions. In addition to the level value in cm−1 and the parity, the J value and the configuration and term assignments are listed if known. Leading percentages from the calculated eigenvectors are tabulated wherever available. Ionization energies are given for all spectra.

Energy Levels of Silicon, Si I through Si XIV

Energy level data are given for the atom and all positive ions of silicon (Z=14). These data have been critically compiled, mainly from published material on measurements and analyses of the optical spectra. We have derived or recalculated the levels for a number of the ions. In addition to the level value in cm−1 and the parity, the J value and the configuration and term assignments are listed if known. Leading percentages from the calculated eigenvectors are tabulated or quoted wherever available. Ionization energies are given for all spectra. Key words: atomic energy levels; atomic ions; atomic spectra; electron configurations; ionization potentials; silicon.

Proposed Secondary-Standard Wavelengths in the Spectrum of Thorium*

Energy levels for Th i were computed from the weighted averages of wavelengths from seven sets of published interferometrically measured data. The most self-consistent energy levels obtained in this way were then employed to calculate wavenumbers that have a standard deviation of less than 10 mK. We propose that these lines be adopted as class-B secondary standards. Calculated wavelengths of 1375 Th i lines and weighted averages of 181 interferometrically measured Th i and Th ii lines between 2565 and 12 381 A are given.

Energy Levels of Sulfur, S I Through S XVI

Energy level data are given for the atom and all positive ions of sulfur (Z=16). These data have been critically compiled, mainly from published and unpublished material on measurements and analyses of the optical spectra. We have derived or recalculated the levels for a number of the ions. In addition to the level values in cm−1 and the parity, the J value and the configuration and term assignments are listed if known. Leading percentages from the calculated eigenvectors are tabulated or quoted wherever available. Ionization energies are given for all spectra.

Energy levels of phosphorus, P I through P XV

Energy level data are given for the atom and all positive ions of phosphorus (Z=15). These data have been critically compiled, mainly from published and unpublished material on measurements and analyses of the optical spectra. We have derived or recalculated the levels for a number of the ions. In addition to the level values in cm−1 and the parity, the J value and the configuration and term assignments are listed if known. Leading percentages from the calculated eigenvectors are tabulated or quoted wherever available. Ionization energies are given for all spectra.

Energy levels of aluminum, Al I through Al XIII

Energy level data are given for the atom and all positive ions of aluminum (z=13). These data have been critically compiled, mainly from published material on measurements and analyses of the optical spectra. We have derived or recalculated the levels for a number of the ions. In addition to the level value in cm−1 and the parity, the J value and the configuration and term assignments are listed if known. Leading percentages from the calculated eigenvectors are tabulated wherever available. Ionization energies are given for all spectra.

Energy levels of sodium Na I through Na XI

Energy level data are given for the atom and all positive ions of sodium (Z = 11). These data have been critically compiled, mainly from published material on measurements and analyses of the optical spectra. We have derived or recalculated the levels for a number of the ions. In addition to the level value in cm−1 and the parity, the J value and the configuration and term assignments are listed if known. Leading percentages from the calculated eigenvectors are tabulated wherever available. Ionization energies are given for all spectra.

PRESENT STATE OF ANALYSIS OF THE FIRST SPECTRUM OF THORIUM (Th I).

To date 268 even and 255 odd atomic energy levels in Th i have been found. The lowest level of the configuration 5f 6d 7s2 is 3H40 and lies 7795.27 cm−1 above the ground level 3F2 of 6d2 7s2. Some levels of 5f 6d2 7s and 6d2 7s 7p are identified.

4s 2 4p 4 –4s4p 5 transitions in five-times-ionized yttrium (Yvi)

The spectrum of yttrium has been observed in a sliding spark discharge at peak currents up to 2000 A on the 10.7 m normal and grazing incidence vacuum spectrographs at NBS. From these observations, the group of 4s24p4–4s4p5 transitions in Yvi, which lie in the region 457–766 A, has been identified and measured, thus yielding values for the 4 levels of the 4s4p5 configuration and revised values for the 5 levels of the 4s24p4 configuration. The energy parameters obtained from a least-squares fit to the observed levels are compared with Hartree-Fock calculations.