Kar, S, Ho YK.
2008.
Unnatural parity states of helium with screened Coulomb potentials. International Journal of Quantum Chemistry. 108:1491–1504., Number 9: Wiley Subscription Services, Inc., A Wiley Company
AbstractEffect of screened Coulomb (Yukawa) potentials on the doubly excited meta-stable bound states and the resonance states with unnatural parities of the helium atom have been investigated in the framework of stabilization method using CI-type basis functions. A total of 54 resonances (6 each of 1Do and 3Do states, 12 each of 1Fe and 3Fe states, 9 each of 1Go and 3Go states) below the He+(3P) thresholds have been estimated by calculating the density of resonance states using a stabilization method. The resonances belong to the different 3lnl′ (n ≥ 3) series. We have also calculated the doubly excited 1,3Fe and 1,3Go meta-stable bound states of He atom below the He+ (2P) thresholds. The resonance energies and widths along with the meta-stable bound states energies are reported for various screening parameters. In free atom case, some of the F-wave resonance states and most of the cases, F- and G-wave resonance widths are reported for the first time. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2008
] 
