We report in this paper on the ENn energy resonances of the doubly excited 1P° states of H^- and He below the N = 4-10 threshold of H and He^+, applying the modified orbital atomic theory in the framework of a semi-empirical procedure. The calculated energy levels are specified in terms of the supermultiplet classification scheme based on the new notations N(K, T)n^A and N(ν)n^A in the framework of the rovibrator model for the autoionizing states considered. Comparison of the N ⟨r12^(-1) ⟩n radial expectation values of H^- and He indicates that the angular quantum number K is effectively related to -⟨cos θ12⟩, with θ12 being the angle between the position vectors of the two electrons. In addition, comparison of the radial expectation values of H^- and He shows that, for both intrashell and intershell N(K, T)n^A , 1P° states, it is the Coulomb force which causes the differences observed in the photoabsorption spectra of H^- and He. All the results presented in this work compared well with the available literature values.