Revised analysis of the third spectrum of mercury: Hg III

Abstract

The doubly charged mercury (Hg III) is having the closed sub-shell 5d10(1S0) as its ground state and the first exited configuration(s) of the type 5d9nl (n ≥ 5). The spectrum of mercury was recorded on a 3-m normal incidence vacuum spectrograph at the spectroscopy laboratory of St. F. X. University in Canada. The excitation source used was a triggered spark in the wavelength region of 300–2000 Å. The theoretical calculations (inclusive of extended configurations) for the ion were accomplished by means of Cowan's quasi-relativistic Hartree-Fock code with superposition of configurations for appropriate interpretation of energy levels. Least squares fitted parametric calculations were used to elucidate the observed level structure. The obtained energy level values were optimized using a level optimization program (LOPT). A gross set of energy eigenvalues along with their LS-compositions, wavelengths and weighted transition probabilities of Hg2+ in the wavelength range 590 Å to 8200 Å are given. The ionization potential of Hg III was found to be 278,200 ± 400 cm−1 (34.49 ± 0.05 eV).