Relativistic energies and auger widths of high-lying doubly-excited states 1s²3lnl′ ¹D^e in Be-Like O⁴⁺ Ions

The saddle-point variational method and restricted variational method are used to calculate energies of doubly-excited singlet states 1s ²3lnl′ (n 3-5) ¹D^e in Be-like O ⁴⁺ ions, including the mass polarization and relativistic corrections. The saddle-point complex-rotation method is used to compute the Auger widths and Auger transition rates. These results are compared with other theoretical and experimental data in the literature.