Calculation of doubly excited 1Se states of Li+ using a B-spline based spectral approach of configuration type combined with the complex rotation method

We report in the present paper accurate computed resonant parameters for the doubly excited S-1(e) states of the He-like Li+ ion lying below the N = 2 and N = 3Li(2+)(Nl) hydrogenic thresholds. Our theoretical method is based on the diagonalization of the two-electron Hamiltonian using the complex rotation technique with B-spline functions. The present method enables to locate the resonances in the energy spectrum of the ion with a precise and simultaneous calculation of their energy positions and lifetimes. The obtained results are in very good agreement with other available experimental and theoretical data.