Madden, R.P. and Codling, K. (1965) Two-Electron Excitation States in Helium. The Astrophysical Journal, 141, 364-375.
https://doi.org/10.1086/148132

has been cited by the following article:

• TITLE: Energy Positions of the 1,3De Rydberg Series of the He-Like Ions Up to the N = 9 Threshold

  AUTHORS: Matabara Dieng, Babou Diop, Malick Sow, Youssou Gning, Mamadi Biaye, Ababacar Sadikhe Ndao, Ahmadou Wagué

  KEYWORDS: Electronic Correlations, Variational Calculations, Atoms And Ions, Helium-Like Systems, Singlet States, Triplet States, Matrix Elements, Doubly-Excited States, Autoionization

  JOURNAL NAME: Journal of Applied Mathematics and Physics, Vol.8 No.8, August 20, 2020

  ABSTRACT: The doubly excited states of helium-like ions are investigated using a combination of the no-linear parameters of Hylleraas and the β-parameters of screening constant by unit nuclear charge. Calculations are performed for total energies of low-lying doubly excited states (N = 2 - 9) in He-like ions up to Z = 10. The results obtained from the novel method are in good agreement with the available theoretical calculations and experimental observations.