Table 8. Energy positions (−E) for doubly excited Npnp 1De (n = 3 – 12) states of Helium-like ions (Z = 2 – 10) below the N = 3 – 8 hydrogenic thresholds. Comparison is made with other theoretical results. The results are expressed in atomic units

From

Doubly-Excited 1,3Se, 1,3P0, 1,3De, 1,3F0 and 1,3Ge Resonances States of Two-Electron Atoms below the N = 3 – 8 Hydrogenic Thresholds

M.T. Gning, I. Sakho

International Journal of Physics. 2022, 10(1), 23-48 doi:10.12691/ijp-10-1-2