The construction of a photoabsorption spectrum using the FEFF 9 package: a detailed procedure

A procedure to obtain a photoabsorption spectrum assembled from first-principles calculations made with the FEFF 9 spectroscopy package is presented. The calculation consists of obtaining the absorption cross-section of electromagnetic radiation for each electronic shell of an atom inside a solid; the total value is obtained by the sum of the contributions of all shells. A complete spectrum is shown for metallic copper as an example, covering values from ultraviolet above 10 eV (approximately) to x-rays. The spectrum is compared selectively with values from frequently used tables and with results taken from the literature. The advantages of the FEFF 9 package and its limitations are compared; as well, the preliminary nature of the presented results and the need for convergence studies are highlighted, suggesting future work.

The 5d-6p VUV Photoabsorption Spectrum of Bi+

The photoabsorption spectrum of Bi+ was measured in the wavelength range between 37 and 60 nm, using the dual laser plasma technique in which one plasma is used as the source of vacuum ultraviolet continuum radiation and the other plasma is used as the sample of atoms and/or ions to be probed. A number of features in the Bi+ spectrum was identified with the aid of the Cowan suite of atomic codes. The 5d → 6p transitions from the ground configuration (5d106s26p2) gave rise to the most prominent features in the measured spectrum. Transitions from low-lying excited states associated with the four excited configurations, 5d106s26p6d, 5d106s26p7s, 5d106s26p7p and 5d106s6p3, were found to make small contributions to the observed spectrum in the 47–50 nm spectral region. To the best of our knowledge, for Bi+, this spectral region is rather unexplored and spectroscopic data are absent from the literature.