Highly precise energy values for the first 14 ${{}^{3}P}^e$ bound states of helium arising out of two electrons having equal azimuthal quantum number are being calculated by using Ritz variational method. The present calculated upper bound energies are lowest yet obtained. Resonance energies and widths for a wide range of resonance states $\left({{}^{3}P}^e\right)$ of helium below $N=3–5$ ionization threshold of ${\text{He}}^{+}$ have also been evaluated by using stabilization method. The present resonance parameters for the region below $N=3–5$ ionization threshold of ${\text{He}}^{+}$ are in excellent agreement with the few available accurate theoretical results. Moreover in the present paper, the resonance parameters of ${{}^{3}P}^e$ resonance states below $N=6$ and 7 ionization thresholds of ${\text{He}}^{+}$ are also reported.

• Received 22 April 2009

DOI:https://doi.org/10.1103/PhysRevA.80.022513