Excitation energies, oscillator strengths, and lifetimes of levels along the gold isoelectronic sequence

Abstract

Energies of ns[1/2] (n= 6-9), np[j] (n = 6-8), nd[j] (n= 6-7), and 5f[j] states in neutral Au and Au-like ions with nuclear charges Z = 80 - 83 are calculated using relativistic many-body perturbation theory. Reduced matrix elements, oscillator strengths, transition rates and lifetimes are determined for the 30 possible nl[j]-n'l'[j'] electric-dipole transitions. Results for a limited number states ns[1/2], np[j] (n= 6-7) and 6d[j] are obtained in the relativistic single-double (SD) approximation, where single and double excitations of Dirac-Fock wave functions are included to all orders in perturbation theory. Using SD wave functions, accurate values are obtained for energies of the eight lowest states and for the fourteen possible electric-dipole matrix elements between these states. With the aid of the SD wave functions, we also determine transition rates and oscillator strengths for the fourteen transitions together with lifetimes of 6p[j], 7p[j], and 6d[j] levels. We investigate the hyperfine structure in HgII and TlIII. The hyperfine A-values are determined for 6s[1/2] and 6p[j] states in 199Hg+, 201Hg+, and 205Tl++ isotopes. These calculations provide a theoretical benchmark for comparison with experiment and theory.