Extended and revised analysis of singly ionized tin: Sn II

Abstract

The electronic structure of singly ionized tin (Sn II) is partly a one-electron and partly a three-electron system with ground configuration 5s25p. The excited configurations are of the type 5s2nℓ in the one-electron part, and 5s5p2, 5p3 and 5s5pnℓ (nℓ = 6s, 5d) in the three-electron system with quartet and doublet levels. The spectrum analyzed in this work was recorded on a 3 m normal incidence vacuum spectrograph of the Antigonish laboratory (Canada) in the wavelength region 300 Å–2080 Å using a triggered spark source. The existing interpretation of the one-electron level system was confirmed in this paper, while the 2S1/2 level of the 5s5p2 configuration has been revised. The analysis has been extended to include new configurations 5p3, 5s5p5d and 5s5p6s with the aid of superposition-of-configurations Hartree–Fock calculations with relativistic corrections. The ionization potential obtained from the ng series was found to be 118 023.7(7) cm−1 (14.633 07(8) eV). We give a complete set of critically evaluated data on energy levels, observed wavelengths and transition probabilities of Sn II in the range 888–10 740 Å involving excitation of the n = 5 electrons.