Electric-field effects on the N=3 ${}_{}{}^1{}_{}{}^{}$${\mathit{P}}^{\mathit{o}}$(1) resonance of ${\mathrm{H}}^{\mathrm{-}}$ are investigated theoretically using a method of complex-coordinate rotation. Products of Slater orbitals are used to represent the two-electron wave functions with ${\mathit{l}}_{\max }$=5 employed for individual electrons. Block matrices with up to ${\mathit{L}}_{\max }$=6 are used. Convergence behavior for the resonance parameters is examined by using different values of ${\mathit{L}}_{\max }$ and ${\mathit{l}}_{\max }$. Results for the energy position and width of the N=3 ${}_{}{}^1{}_{}{}^{}$${\mathit{P}}^{\mathit{o}}$(1) resonance under the influence of external electric fields are compared with experimental observations.

• Received 16 August 1994

DOI:https://doi.org/10.1103/PhysRevA.50.4941