Energies of doubly excited 1,3P° resonances in He-like (Z=2-40) systems below the N=3 hydrogenic threshold

Eight doubly excited 1,3P° resonances in He-like systems below the N=3 hydrogenic threshold are investigated in the framework of Screening Constant by Unit Nuclear Charge (SCUNC) formalism. The Rydberg series investigated are labelled in the (K, T, A) classification scheme. Accurate data are tabulated for the entire He-isoelectronic sequence up to Z=40 with 3≤n≤9, n the principal quantum number of the outer electron.