Hylleraas basis calculation of the doubly excited 1,3Ge states in heliumlike ions

For the ions of the helium isoelectronic sequence (Z = 1 - 10) the resonance parameters (positions and widths) of the doubly excited Feshbach resonances of the 1,3Ge symmetries associated with the N = 3 and N = 4 thresholds of the corresponding hydrogenlike ions have been calculated. The calculations have been carried out by using the complex rotation method, and highly-correlated Hylleraas-type wave functions are used as basis functions.