Energy, fine structure, and transition rate of the doubly excited ³P^e and ³D^e states for helium

Energies and fine-structure corrections for the doubly excited ³P^e and ³D^e states of the helium atom are calculated using the Rayleigh-Ritz variational method and the saddle-point variational method with a multiconfiguration-interaction function. The relativistic and mass polarization corrections are included. The oscillator strengths, transition rates, and wavelengths are also calculated. The doubly excited states are grouped in Rydberg series labeled by the quantum numbers K, T, and A to display the systematic regularity along the series. The results are compared with the theoretical and experimental data in the literature.